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| December 19, 2007 - Ocean Update Vol. 12 No. 8
| Please click the link below to view Ocean Update, now available in PDF form.
In this issue:
- Small-scale Fisheries Shown to Jeopardize Loggerhead Turtle Populations
- Review Examines Viruses in the Ocean
- Report Calls for Stricter Controls, Conservation Measures in Tuna Fisheries
- U.S. Court Restores Injunction Against Military Sonar while Scientists Review its Impact on Cetaceans
- Study Reviews Ecological, Economic and Social Importance of Coasts
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| October 03, 2007 - Ocean Update Vol. 12 No. 7
| Please click the link below to view Ocean Update, now available in PDF form.
In this issue:
- Paper Contrasts Coral Reef Conservation in Western, Pacific Island Nations
- More Bad News for Arctic Sea Ice, Polar Bears
- Studies Show Warming in Northern European Seas, Impact on Fisheries
- Survey Reveals Invasive Range Expansion by Humboldt Squid in Eastern North Pacific
- Genetic Study Questions Past Numbers, Present Status of Eastern North Pacific Gray Whale Populations
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| August 09, 2007 - Ocean Update Vol. 12 No. 6
| Please click the link below to view Ocean Update, now available in PDF form.
In this issue:
- Is "Scientific Reticence" Downplaying the Urgency of Sea Level Rise?
- Basking Shark Trade Continues, Putting Species at Risk. says Study
- Endangered Species Act may be Warranted for Penguins, says Government
- Eggshell Analysis Shows Whaling, Sealing, Have Brought About Changes in Adelie Penguin Diet, says Study
- Survey Reveals Unknown Species, Diversity in Southern Ocean Deep Sea
- Hot off the Press
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| July 11, 2007 - Ocean Update Vol. 12 No. 5
| Please click the link below to view Ocean Update, now available in PDF form.
In this issue:
- CITES Delegates Retreat from Red Coral Protection
- International Whaling Commission Grants Subsistence Quotas, Resists Commercial Hunts, Censures Lethal Research
- Fishing Pressures may have Prompted Evolutionary Response in Cod
- Researches Demonstrates Link Between Warmer Temperatures, Coral Disease
- Study in Borneo Documents Impacts on Live Fish Trade
- Analysis Shows that Extinct Sea Mink was a Separate Species
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| May 10, 2007 - Ocean Update Vol. 12 No. 4
| Please click the link below to view Ocean Update, now available in PDF form.
In this issue:
- Prompt Management Measures Lead to Greater Fish Stock Protection, Recovery
- Other Fisheries, as well as Longlines, may be Causing Sea Turtle Mortality and Declines
- Climate Change Could Lead to Porpoise Starvation
- North Sea Headed For “More Gelatinous Future” As a Result of Climate Change
- Mycobacteria Infections Widespread among Fish in Chesapeake Bay, says Study
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| May 04, 2007 - Ocean Update - Quick Reader Survey
| Dear Ocean Update Subscriber,
In order to better conserve natural resources and minimize expenses related to postage and printing, SeaWeb has ceased production of the print edition of Ocean Update and encourages subscribers to sign up for the electronic version. We would like to thank you for your patience and understanding during this transition, and want to assure you that we will continue to highlight the latest and most ground-breaking marine conservation science for our readers.
As we continue looking for ways to provide the best ocean science publication possible, we invite you to take a brief survey regarding the format and content of Ocean Update. It will take only a few minutes to complete, and the answers will be extremely helpful as we chart the future course of Ocean Update.
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| April 04, 2007 - Ocean Update Vol. 12 No. 3
| April 2007 - Vol. 12 No. 3
Article Considers Impacts of Bering Sea Regime Shift on Steller Sea Lion Populations
A recent paper in the journal Fisheries Oceanography examines whether declines in Steller sea lion populations in the Bering Sea and Gulf of Alaska “could be a consequence of physical oceanographic changes associated with the 1976–77 climate regime shift.” During that climate shift, write authors Andrew Trites of the University of British Columbia and colleagues: “Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions.”
The authors note that Steller sea lion populations dropped by 80 percent between the late 1970s and early 1990s in the western Gulf of Alaska and in the Aleutian Islands, with concurrent declines further west in Russian waters. However, to the east, along the coasts of Southeast Alaska, British Columbia, Washington, and Oregon, sea lion numbers increased through the 1980s and 1990s.
“Much of the search for why Steller sea lions declined in western Alaska has focused on trying to identify a single cause for the changes, rather than recognizing that many of the proposed theories are interrelated,” write the authors. They argue that “the leading hypotheses of epidemic diseases, predation by killer whales, ocean climate change (regime shifts), and nutritional shifts in types of prey available to sea lions (the junk food hypothesis) may all be linked through bottom-up processes. Conceptually, changes in water temperatures, ocean currents and other oceanographic variables can influence the survival and distribution of assemblages of species that are consumed by predators such as sea lions. This in turn will affect the quantity, quality and accessibility of the prey that sea lions consume. Individuals that consume sufficient energy will typically be fat and large, and experience reduced levels of oxidative stress at a cellular level. In contrast, inadequate nutrition can increase oxidative stress (and susceptibility to disease), reduce body fat (and pregnancy rates), and increase rates of predation (as a function of reduced body size or increased vulnerability while spending longer times searching for prey).”
While emphasizing that an ocean climate hypothesis does not discount other explanations for the Steller sea lion declines, but rather “provides a holistic framework within which each of the alternative hypotheses can be aligned,” the authors nonetheless argue that: “The ethnohistoric and archaeological records indicate that the decline of Steller sea lions observed through the 1980s and 1990s was not the first time such an event has occurred. Sea lions appear to have experienced major shifts in numbers long before the advent of commercial fisheries. While fisheries could be a confounding factor in the current decline, ocean climate appears to be the only major driving force that can link changes over so many eras and across so many trophic levels.”
Source: Trites, A.W., et al. 2007. Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatas) in Alaska: assessing the ocean climate hypothesis. Fisheries Oceanography 16:1, 46-67.
Contact: Arthur J. Miller, Scripps Institution of Oceanography. E-mail.
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Seagrass Ecosystems Facing “Global Crisis”
“Seagrasses—a unique group of flowering plants that have adapted to exist fully submersed in the sea—profoundly influence the physical, chemical, and biological environments in coastal waters, acting as ecological engineers and providing numerous important ecological services to the marine environment. Seagrasses alter water flow, nutrient cycling, and food web structure. They are an important food source for megaherbivores such as green sea turtles, dugongs, and manatees, and provide critical habitat for many animals, including commercially and recreationally important fishery species. They also stabilize sediments and produce large quantities of organic carbon.”
So begins a paper by Robert J. Orth and others in the journal BioScience.
However, Orth—of the Virginia Institute of Marine Science at the College of William and Mary—and his co-authors note that “seagrasses and these associated ecosystem services are under direct threat from a host of anthropogenic influences.”
The authors note that the rates of change in coastal waters are greater today “than those experienced in 100 million years of evolutionary history.” Among the documented impacts on seagrasses, operating on a variety of scales, are “global climate change (e.g., increases in sea surface temperature, sea level, and frequency and intensity of storms and associated surge and swells), from regional shifts in water quality (e.g., in the Chesapeake Bay), and from more localized impacts due to increased loading of sediment, contaminants, and nutrients reaching coastal environments (e.g.,Cockburn Sound),” all of which “have had demonstrable impacts on the health of seagrass-dominated coastal ecosystems worldwide.”
Furthermore, write the authors, other threats are emerging. These include the introduction of non-native species, and the rapid expansion of fish farming and other aquaculture practices. As a result of the combination of all these impacts, they continue, reported cases of seagrass loss “have increased almost tenfold over the last 40 years in both tropical and temperate regions, suggesting increased rates of seagrass decline worldwide.”
The preservation of seagrasses and their associated ecosystem services should, say the authors, “be a global priority.” They conclude: “We believe that the crisis facing seagrass ecosystems can be averted with a global conservation effort, and this effort will benefit not just seagrasses and their associated organisms but also the entirety of coastal ecosystems.”
Source: Orth, R.J., et al. 2006. A global crisis for seagrass ecosys- tems. BioScience 56(12): 987-996.
Contact: Robert J. Orth, Virginia Institute of Marine Science, College of William and Mary. E-mail.
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Ecosystem-Based Management Often Stronger In Theory Than in Practice, Says Paper
“Over the past decade, policymakers, management agencies, and academic scientists have shown increasing interest in ecosystem- based management (EBM). Yet, the extent that EBM principles, deemed important by scientists, are adopted by managers is still uncertain.” So note Katie K. Arkema, of the University of California, Santa Barbara, and colleagues, writing in the journal Frontiers in Ecology and Environment.
Part of the problem, they argue, is that there is no agreement on a precise definition of ecosystem-based management. Indeed, they reviewed 18 different definitions for the term. “One universal term for, and definition of, ecosystem-based management will clarify the concept and make it more accessible to managers,” they write.
They also note that “scientists characterize EBM differently than agencies planning to manage coastal and marine ecosystems. We found that management objectives and interventions tend to miss critical ecological and human factors emphasized in the academic literature.” They recommend that “communication be improved among scientists, management agencies, and the public to highlight the parallels that exist between ecological and human perspectives and facilitate a better understanding of EBM.”
Source: Arkema, K.K., et al. 2006. Marine ecosystem-based management: from characterization to implementation. Frontiers in Ecology and Environment 4(10): 525-532.
Contact: Katie K. Arkema, Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara. E-mail.
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A Warmer Ocean will lead to Phytoplankton Declines, Says Study
The productivity of phytoplankton is geared to fluctuations in the global climate, and recent warmer temperatures correspond to lower oceanic biomass and productivity. This is the conclusion of a study published in the journal Nature.
The study, by Michael J. Behrenfeld of Oregon State University and colleagues, analyzed a decade of data from satellites which measured surface chlorophyll. Behrenfeld and his co-authors combined these readings with empirical data to estimate phytoplankton growth rates and net primary production. Using this method, the study’s authors found that global chlorophyll and productivity increased sharply from 1997-98, and then declined steadily until 2005.
According to Behrenfeld and colleagues, the sharp increase occurred during a negative, or cold, phase of the El Niño- Southern Oscillation (ENSO), and the subsequent slow drop occurred as the planet moved into a warm phase. In a companion article in Nature, Scott C. Doney of the Woods Hole Oceanographic Institution explains that the “climate–plankton link is found primarily in the tropics and mid-latitudes, where there is limited vertical mixing because the water column is stabilized by thermal stratification (that is, when light, warm waters overlie dense, cold waters). In these areas, the typically low levels of surface nutrients limit phytoplankton growth. Climate warming further inhibits mixing, reducing the upward nutrient supply and lowering productivity.”
Extrapolating these observations into the future, continues Doney, “suggests that marine biological productivity in the tropics and mid-latitudes will decline substantially.” However, ecosystem dynamics are complex and nonlinear, “and unexpected phenomena may arise as we push the planet into this unknown climate state.”
Sources: Behrenfeld, M.J., et al. 2006. Climate-driven trends in con- temporary ocean productivity. Nature 444: 752-755; Doney, S.C., 2006. Plankton in a warmer world. Nature 444: 695-696.
Contact: Michael J. Behrenfeld, Oregon State University. E-mail. Scott C. Doney, Woods Hole Oceanographic Institution. E-mail.
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Decline in Predatory Fish Species Severe, but not yet Catastrophic, According to Study
Fisheries have removed at least 50 million tons of tuna and other top-level predators from the Pacific Ocean pelagic ecosystem since 1950, leading to concerns about a possible catastrophic reduction in population biomass and the collapse of oceanic food chains. A recent paper in the journal Science argues that although the impacts on fish populations have been substantial, they have not yet been catastrophic.
The paper, by John Sibert of the University of Hawaii and colleagues, notes that “industrial fisheries for tunas and associated species extend over most of the tropical and temperate Pacific Ocean and currently produce over 2.5 million tons or about 64 percent of the 2004 global tuna catch.” Although other species are taken, such as bluefin tuna, billfishes, and oceanic sharks, 90 percent of the catch comprises four tuna species: skipjack, albacore, yellowfin, and bigeye.
“Data derived from these fisheries (including catch, fishing effort, size composition, and tagging data) show a 50-year record of natural variability in and human impacts on open- ocean ecosystems,” write the authors. “We analyzed all available data with state-of-the art stock assessment methods to provide estimates of fishery impacts on population biomass, size structure, and trophic status of major top-level predator stocks in the Pacific Ocean: bigeye tuna, yellowfin tuna, skipjack tuna, albacore tuna, and blue shark.”
Their results indicated a great deal of variation among different stocks. According to the authors, western Pacific yellowfin and bigeye tuna have declined steadily, skipjack tuna and blue shark appear to have increased slightly, and albacore have fluctuated in both directions. “Current total and adult biomass range, respectively, from 36 percent to 91 percent and 12 percent to 89 percent of that predicted in the absence of fishing,” they write. “The variability in biomass over time and among stocks cannot be attributed entirely to fishing.”
Sibert and colleagues argue that, although their results “appear to differ sharply from widely accepted views of the status of large oceanic predatory fish stocks and the ecosystem effects of fishing,” they should in fact be “interpreted as extensions of previous work, providing a more realistic appraisal of the effects of fishing on the pelagic ecosystem.”
The authors do note, however, that the largest fish—those larger than 175 cm—have declined drastically, and express their concern over the depleted state of yellowfin and bigeye stocks. They argue that the relevant international fisheries commissions “need to implement effective conservation measures before stocks reach a state where draconian measures, such as complete closures, are required to preserve the fishery and sustain the ecosystem.”
Source: Sibert, J., et al. 2006. Biomass, size, and trophic status of top predators in the Pacific Ocean. Science 314: 1772-1776.
Contact: John Sibert, University of Hawaii. E-mail.
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Rockhopper Penguins Should Be Classified as Three Separate Species, likely affecting Conservation Status, Say Researchers
Rockhopper penguin populations have decreased markedly, notes a paper in the journal Polar Biology. For example, a survey conducted in 2000/2001 estimated that populations of southern rockhopper penguins in the Falkland Islands have declined to 20 percent of the number present in 1932/33, while eastern rockhopper penguins breeding on Campbell Island have decreased from an estimated 1.6 million breeding birds in 1942 to 103,000 birds in 1985. According to the authors of the paper, “It has been suggested that competition with fishing fleets for prey, oil exploitation, introduced predators, human collection of eggs, hunting of adults for fishing bait and/or increasing sea temperatures are responsible for the decline.”
The authors—Jonathan Banks of the University of Illinois and colleagues—note that, because of such declines, the World Conservation Union (IUCN) classified the rockhopper as “vulnerable” in 2000. However, after examining rockhopper DNA and comparing it with other penguin species, Banks and colleagues conclude that instead of one rockhopper species divided into three sub-species, the current classification, rockhopper penguins should in fact be classified as three separate species. They note that: “Reclassification of the three subspecies as full species may result in the conservation status of rockhopper penguins being changed from vulnerable to endangered by the IUCN due to the smaller population size and limited distributions of the new species.”
Source: Banks, J., et al. 2006. Genetic evidence for three species of rockhopper penguins, Eudyptes chrysocome. Polar Biology 30: 61-67.
Contact: Jonathan Banks, University of Illinois. E-mail.
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About Ocean Update
Ocean Update is a free monthly publication of SeaWeb, a communications-based non-profit organization that uses social marketing techniques to advance ocean conservation. The purpose of Ocean Update is to highlight the latest and most groundbreaking science and research related to the marine environment and conservation. Ocean Update reports with deliberate neutrality and does not editorialize nor advocate any of the positions or conclusions it publishes. It is intended to bring readers timely information they might otherwise not see. We welcome financial contributions to assist in the production and dissemination of the Ocean Update. Please visit www.seaweb.org/donate.php. To learn more about SeaWeb, visit www.seaweb.org, write us at contactus@seaweb.org or call us at 301.495.9570. |
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| February 15, 2007 - Ocean Update Vol. 12 No. 2
| February 2007 - Vol. 12 No. 2
Canned Fish Greater Source of Mercury Exposure Than Wild Fish For Pregnant Women In Study
High levels of fish consumption during pregnancy have been frequently associated with health benefits for both mother and child, including longer gestation, increased birth weight, reduced risk of intrauterine growth retardation, and lower prevalence of pregnancy-induced hypertension.
At the same time, however, fish and shellfish, especially species high in the food chain, are potential sources of exposure to pollutants such as methylmercury that may adversely affect pregnancy. A paper in the journal Environmental Health Perspectives notes that, “There is concern that levels of
methylmercury that are not toxic to adults may pose a hazard to the developing fetus.”
The paper, by Fei Xue of the Harvard School of Public Health and colleagues, observes that, “Studies on birth weight and total mercury levels, measured in maternal hair or cord blood, have produced mixed results, with some reporting an inverse relationship and others showing no association. In addition, one study of maternal occupational exposure to metallic mercury found no effect on birth weight.”
As part of a study dubbed the Pregnancy Outcome and Community Health (POUCH) Study, the authors examined mercury levels in hair at mid-pregnancy in more than 1,000 women recruited from five communities in Michigan, which borders four of the five Great Lakes. Fish consumption and corresponding mercury exposure were evaluated in relation to the risk of pre-term delivery (PTD).
Among the study’s major findings was an apparent association between high mercury levels and delivery before 35 weeks’ gestation. However, the authors caution that although the sample size was large, the number of women who delivered before 35 weeks of pregnancy was small, and that therefore “more studies are needed to test this association.”
In general, the authors concluded that, “Our study reinforced previous findings suggesting that fish consumption is a major source of mercury exposure for pregnant women. Although much attention has been focused on pollutants in locally caught fish, and fish advisories are not uncommon, we found that only a small percentage of pregnant women, < 10%, consumed sport-caught fish during pregnancy. The greatest fish source for mercury exposure appeared to be canned fish, both because it was consumed more and, per meal, it was among the fish categories associated with the highest levels of mercury in maternal hair.”
Source: Xue, F., et al. 2007. Maternal fish consumption, mercury levels, and risk of preterm delivery. Ecological Health Perspectives 115 (1): 42-47.
Contact: C.B. Holzman, Michigan State University. Tel: (517) 353 8623, ext. 122. E-mail: holzman@msu.edu
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Review Examines Health Risks, Benefits Associated with Seafood Capture, Handling, and Consumption
A recent paper in the journal Revue scientifique et technique de l’Office internationale des Epizooties has provided a comprehensive overview of the various health risks associated with the capture, handling, production, and consumption of wild and farmed seafood and seafood products.
The first part of the paper “outlines the hazards and challenges associated with handling fish during farming and capture.” The authors describe zoonotic agents (infectious agents that cause disease in fish as well as humans), bacterial infections, and allergies caused by the consumption of fish. They note that, although “only a few infectious agents in fish are able to infect humans, some exceptions exist that may result in fatalities. However, the greatest risk to human health is due to the consumption of raw or insufficiently processed fish and fish products.”
In the second part of the paper, the authors consider contaminants in seafood that may pose a risk to human health, such as medicinal products, residues associated with aquaculture, persistent lipophilic organic compounds, and metals such as methyl-mercury and organotins.
They observe that: “It is well known that fish, particularly oily fish, are an important source of long chain fatty acids, reducing the risk of cardiovascular diseases, as well as having beneficial effects on fetal development. Seafood is also a valuable source of certain minerals, vitamins and protein. However, balanced against this are the possible detrimental effects of contaminants found in certain fish species ...
“It is important to understand the mechanisms and interactions between nutrients and contaminants in seafood if researchers are to give sound scientific advice on the amount and type of seafood that should be recommended to promote health and maximize safety in different groups of the population. At present, there is no agreed methodology for taking both the risks and benefits of seafood into account in a quantitative way.”
Source: Hastein, T., et al. 2006. Food safety hazards that occur during the production stage: challenges for fish farming and the fishing industry. Rev.Sci.Tech.OIE 25(2): 607-625.
Contact: T. Hastein, National Veterinary Institute, PO Box 8156 Dep., N-0033 Oslo, Norway.
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Human Health Problems Associated with Sea Turtle Consumption “May Be Cause for Concern”
Historically, sea turtles have served as an important food source for human populations worldwide, a fact that has contributed significantly to the global decline of sea turtle species. All seven species of sea turtle worldwide are classified as either threatened or endangered. As a result, sea turtle consumption is illegal in much of the world; even so, say the authors of a paper in the journal EcoHealth, “reports of ongoing sea turtle consumption (legal and illegal) have emerged from many parts of the world, including Australia, the Caribbean, the Indian Ocean, Papua New Guinea, the Philippines, Central and South America, Mexico, Egypt, Vietnam, and Madagascar.”
According to the paper’s authors—A. Alonso Aguirre of Columbia University and colleagues—the specifics of sea turtle consumption vary around the world:
“Coastal communities that consume sea turtles generally utilize the entire animal. While turtle meat is eaten directly, internal organs such as kidney and liver are used for soup. Oil is extracted from the fat as a cure for respiratory problems, especially in children, and the blood is drunk raw as a remedy for anemia and asthma. Additionally, sea turtle eggs are valued as an aphrodisiac.
“In Latin America, sea turtles have historically been considered a delicacy served on special occasions such as weddings, Christmas, Mother’s Day, and Easter. In Mexico, where Catholicism is the predominant religion, the consumption of sea turtle meat and eggs increases during Lent. Many Mexican Catholics observe religious restrictions against the consumption of red meat, and consume sea turtles due to the belief that these species are fish. In addition to being a valuable food source, the use of this resource is highly ingrained as part of various regions’ cultural heritages and sea turtle consumption has thus gained traditional importance.”
However, in addition to the pressure that this places on the turtle populations, Aguirre and his co-authors argue that eating sea turtles poses risks for the human consumers.
“Scientific studies from around the globe indicate that sea turtles harbor various contaminants, parasites, bacteria, and biotoxins,” they write. “These hazards have been shown to have deleterious human health effects and, in some instances, cases of illness and death from sea turtle consumption have been documented. The documented cases of human health problems associated with the consumption of sea turtle products may be cause for concern given the worldwide prevalence of this practice.”
They note that much information on the issue “has been the domain of the scientific community, and not the general public or even public health community. Accordingly, it is important to effectively communicate pertinent information regarding the potential human health hazards associated with sea turtle consumption in areas where this practice is common.” Such education, however, should go beyond the issuance of press releases to incorporate a variety of media to “provide information in a form that is easily accessible by the general public.”
Source: Aguirre, A.A. et al. 2006. Hazards associated with the consumption of sea turtle meat and eggs: a review for health care workers and the general public. EcoHealth 3: 141–153.
Contact: Jesse C. Marsh, Monterey Bay Aquarium. E-mail: jmarsh@mbayaq.org
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Cleaning Up Coastal Waters Can Reduce Disease, Costs, Says Study
“Each year between 150 million and nearly 400 million visits are made to California (CA) beaches generating billions of dollars in expenditures, by tourists and local swimmers, and nonmarket values enjoyed mostly by local area residents.” However, “based on water quality criteria and their professional judgment, CA county health officials posted or closed beaches 3,985 days during 2004. Sixty percent (2,408 beach-days) of these occurred at Los Angeles and Orange County (LAOC) beaches, and nearly all (93%) of the LAOC advisories and closures were caused by unknown sources of fecal indicator bacteria.”
So begins a recent study in the journal Environmental Science and Technology. The paper, by Susan Given and Linwood Pendleton of UCLA, and Alexandria Boehm of Stanford University, notes that “the number of beach closures and advisories in CA (and the country as a whole) rises each year as counties monitor more beaches. Needless to say, public awareness of coastal contamination issues is growing, and in some cases strongly influencing the development of programs to improve coastal water quality.”
To understand the potential public health benefits of cleaning up coastal waters, Given and colleagues conducted an analysis of the number of cases of gastrointestinal illness (GI) associated with swimming in contaminated marine waters in Los Angeles and Orange Counties, and on the impact in terms of public health costs and economic losses in the beach areas.
They concluded that “removing fecal contamination from coastal water in LAOC beaches could result in the prevention of between 627,800 and 1,479,200 GI infections and a public health cost of between $21 and $51 million (depending upon the epidemiological model used) each year in the region using the most conservative cost estimates and as much as $176 million or $414 million if we use the larger estimate of health costs.”
Addressing the problem, the authors observe, is not necessarily as straightforward as it may seem:
“Beaches with chronic water quality problems are obvious candidates for immediate contamination mitigation. Many beaches in LAOC, however, are relatively clean and meet water quality standards on most days. Clean beaches with moderate to low levels of attendance do not represent a significant public health burden. Nevertheless, public health impacts are still substantial at heavily visited beaches (for instance those with over 6,000,000 visitors per year) even when water quality is good
(e.g., Manhattan Beach).”
In such circumstances, they argue, policy managers should continue education campaigns and watershed management, to reduce the prospect of contaminated storm water affecting beach areas; but, they assert, “the cost of eliminating all beach contamination may outweigh the marginal public health benefits of doing so.”
Source: Given, S. et al. 2006. Regional public health cost estimates of contaminated coastal waters: a case study of gastroenteritis at southern California beaches. Environmental Science & Technology 40 (16): 4851-4858.
Contact: Linwood H. Pendleton. E-mail: linwoodp@ucla.edu. Tel: (310) 825 8569.
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Human Development Linked to Multiple Water Body Impairments, Says Study
“Accelerated human development in coastal areas is a serious threat to the sustainability of aquatic coastal ecosystems. Forty-four percent of the world’s population lives within 150 km of the coast, and this percentage is even larger in the United States. Understanding the increasing effects of the ever-growing human population on the coastal environment is critical to the development of sound management principles for the protection of both ecosystem health and the health of those who use these waters for recreation.”
So begins a paper in the journal Estuaries and Coasts. The paper’s authors, Nicholas B. Handler of Stanford University and colleagues, collected monthly samples over a 15-month period at 14 fresh, estuarine, and marine waterways along an approximately 100-mile stretch of the California coast. The objective of the study was to identify the effects of land use on pollutant levels across a range of coastal water bodies.
The authors noted there was a particularly strong correlation between land use and quantities of Fecal Indicator Bacteria (FIB) in freshwater sites, notably those where the nearby land use was predominantly agricultural. They suggest that this shows that “dilution of land-based flow by seawater or salinity-induced die-off are important in controlling FIB densities” in the waterways they tested. However, there was a strong correlation between nutrient and chlorphyll-a levels and agricultural land use in all water types. There was a similar correlation in all water types between levels of soluble reactive phosphate (SRP) and urban land use. Of the latter, the authors note that: “In urbanized areas, runoff can deliver fertilizer, detergents, and waste from domesticated animals, municipal waste streams, and failed septic systems, all of which are enriched in SRP.”
The authors conclude that: “Our findings highlight the importance of land management in the protection of human and ecosystem health along the California coast ... As human populations in coastal regions continue to grow, so must our awareness of anthropogenic effects on coastal waters and our strategies to protect them.”
Source: Handler, N.B., et al. 2006. Human development is linked to multiple water body impairments along the California coast. Estuaries and Coasts 29 (5): 860-870
Contact: Alexandria B. Boehm, Stanford University. Tel: (650) 724 9128. E-mail: aboehm@stanford.edu
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About Ocean Update
Ocean Update is a free monthly publication of SeaWeb, a communications-based non-profit organization that uses social marketing techniques to advance ocean conservation. The purpose of Ocean Update is to highlight the latest and most groundbreaking science and research related to the marine environment and conservation. Ocean Update reports with deliberate neutrality and does not editorialize nor advocate any of the positions or conclusions it publishes. It is intended to bring readers timely information they might otherwise not see. We welcome financial contributions to assist in the production and dissemination of the Ocean Update. Please visit www.seaweb.org/donate.php. To learn more about SeaWeb, visit www.seaweb.org, write us at contactus@seaweb.org or call us at 301.495.9570. |
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| January 15, 2007 - Ocean Update Vol. 12 No. 1
| January 2007 - Vol. 12 No. 1
Yangtze River Dolphin “Functionally Extinct”
The baiji, or Yangtze river dolphin, is “in all probability extinct,” according to a multinational team of scientists who conducted a six-week expedition in late 2006.
The scientists were traveling on two research vessels along 2,200 miles of the Yangtze River, using high-performance optical instruments and underwater microphones.
“It is possible we may have missed one or two animals,” said August Pfluger, head of the Swiss-based Baiji.org Foundation and co-organizer of the expedition. However, he continued, “We have to accept the fact that the baiji is functionally extinct. It is a tragedy, a loss not only for China, but for the entire world.”
The dolphin’s apparent demise is considered the result of a combination of habitat destruction, illegal fishing and collisions with ships. In the beginning of the 1980s, the Yangtze was believed to be home to around 400 baiji. However, the river dolphin became a victim of China’s rapidly growing economy. A 1997 survey showed 13 confirmed sightings. The last confirmed sighting of a baiji was in September 2004.
Contact: August Fluger, Baiji.org Foundation. E-mail: august@baiji.org
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UN Rejects Bottom Trawling Ban as Researchers Reveal that Subsidies Keep Draggers Afloat
The United Nations rejected a proposed moratorium on high seas bottom trawling in December, after the government of Iceland rejected efforts to reach a compromise agreement. Instead, the UN General Assembly adopted a non-binding resolution in which countries agreed to increase protection measures under the aegis of regional fishery management organizations. The resolution requires that countries police their own vessels in unregulated waters.
“The final agreement has more loopholes in it than a fishermen’s sweater,” said Karen Sack, oceans policy advisor to Greenpeace.
Eleven nations have high seas bottom trawling fleets, the largest of which is from Spain. A 2004 report for the World Conservation Union (IUCN) concluded that bottom-trawling was “highly destructive to the biodiversity associated with seamounts and deep-sea coral ecosystems and ... likely to pose significant risks to this biodiversity, including the risk of species extinction.” In the same year, 1,100 scientists put their names to a petition supporting the demand for a moratorium.
As the UN was discussing the proposed moratorium, researchers from the University of British Columbia found that perhaps the most effective method of removing bottom trawling fleets from the ocean would be to eliminate the subsidies that keep the fleets afloat.
“At US$152 million a year, the global amount of subsidies paid to bottom trawl fleets constitutes 15 per cent of the total value of the catch,” said UBC Associate Professor Rashid Sumalia, lead author of the study Catching More Bait: A Bottom-up Re-estimation of Global Fisheries Subsidies. “In comparison, the profit of these fleets comes to only 10 per cent of the total catch ...Eliminating government subsidies renders these fleets economically unviable and as a result, relieves enormous pressure on over-fishing and vulnerable deep-sea ecosystems.”
For Further Information: The report, Catching More Bait: A Bottom-up Re-estimation of Global Fisheries Subsidies, is available at http://www.fisheries.ubc.ca/publications/reports/14-6.pdf
Contact: Rashid Sumaila, Fisheries Centre, Aquatic Ecosystems Research Laboratory (AERL), University of British Columbia, 2202 Main Mall, Vancouver, BC., V6T 1Z4, Canada. E-mail: r.sumaila@fisheries.ubc.ca.
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Paper Dissects Japanese Government Views on Whaling
This year’s meeting of the International Whaling Commission (IWC) will take place in Anchorage, Alaska in May. At the meeting, government representatives will again consider, among other things, commercial whaling by Norway and Iceland, and Japan’s “scientific” whaling program in the Antarctic, as well as Japanese claims that whale populations need to be controlled in order to prevent whales from depleting fish stocks.
A forthcoming paper in the journal Marine Policy, by Philip J. Clapham, of the Alaska Fisheries Science Center, and colleagues, addresses some of the claims made by the Government of Japan on behalf of its whaling policy.
For example, the authors counter Japanese assertions that “baleen whales eat a large number of commercially important fish” by pointing out that:
- Many whales do not eat fish at all; indeed, the greatest biomass of the world’s baleen whales live in the Southern Hemisphere, where they primarily consume krill;
- The sizes of many whale populations today are at a small fraction of their levels in pre-whaling times when commercial fish populations were considerably larger and much healthier than they are today;
- The primary predators of fish are not whales, but other fish;
- The removal of top predators (such as cetaceans) can cause major ecosystem perturbations, with negative consequences for fisheries;
- Human over-fishing (not whales) is the cause of the precipitous decline of commercial fish stocks worldwide.
Clapham and colleagues note the tendency of the Government of Japan to cite figures in defense of its arguments even when those figures have been repeatedly questioned or shown to be false. For example, the Japanese whaling industry repeatedly claims that the IWC Scientific Committee has agreed to a figure of 760,000 minke whales in the Southern Hemisphere, even though this figure dates from surveys that concluded in 1988; that more recent analyses suggest a figure closer to 68,000 whales; and that the Scientific Committee has agreed since 2000 that it does not have a reliable estimate of the population of Southern Hemisphere minke whales.
As another example, Clapham and his co-authors note that the website of Japan’s Institute of Cetacean Research (ICR) states, in defense of its assertion that whale populations are increasing rapidly, that populations of fin and humpback whales are increasing at rates of 14-16% annually—a figure, say the writers, that not only has no basis but is “biologically impossible.”
Clapham and colleagues note that, “Left to purely market forces, [the whaling] industry would likely die since Japan’s populace has lost its taste for whale meat and there is currently a growing mountain of unsold product being held in cold storage.” That being so, the question arises of why the Japanese government should work so hard to maintain it. The authors offer their observations at the conclusion of their article:
“[T]o understand the importance of whaling to Japan, the issue must be seen not in isolation but in the much broader context of international fisheries policy. Concessions in other management fora could impact whaling ... But whaling itself represents a potentially slippery slope: a major loss or concession on this issue could potentially have severe ramifications for Japan’s extensive and critically important fisheries agreements elsewhere.”
Source: Clapham, P.J., et al. 2006. The whaling issue: Conservation, confusion, and casuistry. Marine Policy (2006), doi:10.1016/j.marpol.2006.09.004.
Contact: Phillip Clapham, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle WA 98115. E-mail: phillip.clapham@noaa.gov.
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UN Report Analyzes State of World Aquaculture
“Aquaculture is developing, expanding and intensifying in almost all regions of the world, except in sub-Saharan Africa. Global population demand for aquatic food products is increasing, the production from capture fisheries has leveled off, and most of the main fishing areas have reached their maximum potential. Sustaining fish supplies from capture fisheries will, therefore, not be able to meet the growing global demand for aquatic food. Aquaculture appears to have the potential to make a significant contribution to this increasing demand for aquatic food in most regions of the world; however, in order to achieve this, the sector (and aquafarmers) will face significant challenges.”
So begins a new report by the Food and Agriculture Organization (FAO) of the United Nations, entitled State of World Aquaculture: 2006.
The report outlines a number of global trends in aquaculture production, among them:
- Continuing intensification of aquaculture production: As the availability of additional sites for aquaculture begins to diminish, existing aquaculture production systems are being increasingly intensified. The report notes that, “Intensification may sustain profitability of farming operations, but this comes at a cost. There are management issues (water and health in particular) associated with intensification and the environmental carrying capacity and regulatory concerns that relate to increased numbers or intensity of farms. Not all farmers are able to intensify and, as production costs rise, part of the sector may reduce intensity to lower costs or reduce vulnerability to health or environmental problems. Under appropriate circumstances, there are opportunities for organic aquaculture to play a role and this may become an economically viable form of management.”
- Continuing diversification of species use: Countries are continuing to introduce species or strains for aquaculture, while efforts are made to develop specific strains for aquaculture, particularly the high-value species. The report observes that, “although countries are endeavoring to comply with international norms and standards for the movement and introduction of live aquatic organisms, commercially driven movements and introductions that are not responsible are also evident in many regions of the world.”
- Continuing diversification of production systems and practices: As some traditional agricultural systems become increasingly uneconomic there has been a trend to promote or enable diversification. This may take the form of conversion from agriculture to aquaculture (e.g. rice land for aquaculture) or the integration of aquaculture into existing farming systems. People enter into such diversification to increase their earning capacity, without giving up their primary occupation as farmers.
- Increasing influence of markets, trade, and consumers: There is a trend of increasing fish consumption in many countries (although consumption appears to be declining in much of sub-Saharan Africa), and the choice of species for farmers is becoming geared to the demand for products in the international markets. The report notes that, “Ecolabelling is often considered as no more than a marketing tool. However, with the increasing concern on environmental issues among the consumers worldwide, products that are grown in a responsible manner without harm to the environment are gaining a competitive edge particularly in the developed countries.”
- Enhancing regulation and improving governance of the sector: The report claims that “there is a general trend toward improving governance in aquaculture development and management.” It further states that, “It is clear that in some countries there is need to develop specific aquaculture legislation to better regulate the sector. The increasing requirement for traceability and certification is now leading towards adoption of mandatory registration of aquaculture facilities as part of national legislation.”
For Further Information: The full report is available at ftp://ftp.foa.org/FI/DOCUMENT/t500_advanced/advanced_t500e.pdf.
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Report Examines Using Trade and Marketplace Measures to Promote Sustainable Seafood
A new report, issued jointly by the International Center for Trade and Sustainable Development (ICTSD) and the High Seas Task Force, examines “the use of trade-related fisheries policies and rules that are supportive of sustainable resource management objectives.”
The report notes that “poor fisheries management and inappropriately designed subsidies to fishing industries have been widely recognized as the key economic drivers of overexploitation of fisheries resources by contributing to significant overcapacities of fishing fleets, particularly in developed countries.” It continues: “Large-scale industrial fleets combined with poor or no management have also contributed to secondary pressures on marine resources, such as increased levels of bycatch – that is, species that are caught unintentionally by fishing gear – and the use of destructive fishing practices which harm non-target species and marine ecosystems.”
A number of trade and marketplace measures have been introduced as part of a broader suite of management steps, designed to address some of the problems caused by fisheries management. These include, for example, import bans imposed by Regional Fisheries Management Organizations (RFMOs) on fish products from countries that have been found to contravene RFMO arrangements or regulations. In addition, at the domestic level, “some countries have introduced traceability and labeling schemes for fish and fish products. Marketplace measures, such as eco-labeling schemes or other industry initiatives, aim to provide appropriate market incentives by offering a competitive advantage for sustainably harvested fish products.”
However, “it remains unclear to what extent such measures have actually been effective in encouraging sustainable fisheries management and providing a sufficient market advantage and price premium for sustainably harvested fish products. Developing countries in particular lack the capacity to take advantage of market opportunities and to comply with multilateral management requirements. Questions also remain over the compatibility of these measures with the rules of the World Trade Organization (WTO).”
The report describes and assesses trade measures currently employed under multilateral fisheries management agreements to promote sustainable fishing; examines the role of civil society groups and private sectors in promoting sustainable fishing through marketplace measures; and offers conclusions and recommendations for improving and expanding the use of those measures.
For Further Information: The report, Trade and Marketplace Measures to Promote Sustainable Fishing Practices is available online at http://www.ictsd.org/pubs/itcsd_series/nat_res/Roheim_
Sutimen_2006.pdf.
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About Ocean Update
Ocean Update is a free monthly publication of SeaWeb, a communications-based non-profit organization that uses social marketing techniques to advance ocean conservation. The purpose of Ocean Update is to highlight the latest and most groundbreaking science and research related to the marine environment and conservation. Ocean Update reports with deliberate neutrality and does not editorialize nor advocate any of the positions or conclusions it publishes. It is intended to bring readers timely information they might otherwise not see. We welcome financial contributions to assist in the production and dissemination of the Ocean Update. Please visit www.seaweb.org/donate.php. To learn more about SeaWeb, visit www.seaweb.org, write us at contactus@seaweb.org or call us at 301.495.9570. |
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