Rosenberg
Andrew A.
Rosenberg
Andrew A.
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PreprintSaving endangered whales at no cost( 2006) Myers, Ransom A. ; Boudreau, Stephanie A. ; Kenney, Robert D. ; Moore, Michael J. ; Rosenberg, Andrew A. ; Sherrill-Mix, Scott A. ; Worm, BorisThe North Atlantic right whale is one of the most critically endangered marine species. Drastic overexploitation has driven this large, slow-swimming baleen whale to virtual extinction in Europe, while a small remnant population of ~350 individuals remains on the U.S. and Canadian east coast. Although this species has been protected for 70 years, recovery has been slight and extinction is still looming because of accidental mortality from shipstrikes and fishing gear (Figure 1A,B). Seventy five percent of appropriately photographed whales show evidence of entanglement, predominantly with lobster fishing gear, and this percentage has increased from 52% in the 1980s. At the same time, the U.S. lobster fishery is severely overexploited (the inshore fishing mortalities in the two main U.S. regions are 0.69 and 0.84, while 0.2 achieves maximum yield per recruit). We argue here that this endangered whale species can be protected from entanglement mortality, and the fishery can benefit simultaneously, by a large reduction of lobster traps used; a classic win–win situation.
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ArticleThe history of ocean resources : modeling cod biomass using historical records(Ecological Society of America, 2005-03) Rosenberg, Andrew A. ; Bolster, W. Jeffrey ; Alexander, Karen E. ; Leavenworth, William B. ; Cooper, Andrew B. ; McKenzie, Matthew G.Managing the remnants of the ocean's resources is a critical issue worldwide, but evidence for what constitutes a healthy fish population remains controversial. Here, we use historical sources to understand ecosystem trends and establish a biomass estimate for a key marine species prior to the industrialization of fishing. Declining trajectories have been described for predatory fishes and complex coral reef systems globally, but few numerical estimates of past abundance exist. We combined historical research methods and population modeling to estimate the biomass of cod on Canada's Scotian Shelf in 1852. Mid 19th-century New England fishing logs offer geographically specific daily catch records, describing fleet activity on fishing grounds with negligible incentive to falsify records. Combined with ancillary fishery documents, these logs provide a solid, reliable basis for stock assessment. Based on these data we estimate a biomass for cod of 1.26 × 106 mt in 1852 – compared with less than 5 × 104 mt of total biomass today. In the current policy debate about rebuilding depleted fisheries and restoring marine ecosystems, it is important to recognize that fisheries for key commercial species like cod were far more productive in the past. As we attempt to rebuild these fisheries, our decisions should reflect real and realistic goals for management, not just recently observed catch levels.
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ArticleAssessing the health of the U.S. west coast with a regional-scale application of the Ocean Health Index(Public Library of Science, 2014-06-18) Halpern, Benjamin S. ; Longo, Catherine ; Scarborough, Courtney ; Hardy, Darren ; Best, Benjamin D. ; Doney, Scott C. ; Katona, Steven K. ; McLeod, Karen L. ; Rosenberg, Andrew A. ; Samhouri, Jameal F.Management of marine ecosystems increasingly demands comprehensive and quantitative assessments of ocean health, but lacks a tool to do so. We applied the recently developed Ocean Health Index to assess ocean health in the relatively data-rich US west coast region. The overall region scored 71 out of 100, with sub-regions scoring from 65 (Washington) to 74 (Oregon). Highest scoring goals included tourism and recreation (99) and clean waters (87), while the lowest scoring goals were sense of place (48) and artisanal fishing opportunities (57). Surprisingly, even in this well-studied area data limitations precluded robust assessments of past trends in overall ocean health. Nonetheless, retrospective calculation of current status showed that many goals have declined, by up to 20%. In contrast, near-term future scores were on average 6% greater than current status across all goals and sub-regions. Application of hypothetical but realistic management scenarios illustrate how the Index can be used to predict and understand the tradeoffs among goals and consequences for overall ocean health. We illustrate and discuss how this index can be used to vet underlying assumptions and decisions with local stakeholders and decision-makers so that scores reflect regional knowledge, priorities and values. We also highlight the importance of ongoing and future monitoring that will provide robust data relevant to ocean health assessment.