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Portland, ME, United States

Kerr L.A.,Gulf of Maine Research Institute | Cadrin S.X.,University of Massachusetts Dartmouth | Kovach A.I.,University of New Hampshire
ICES Journal of Marine Science

A mismatch between the scale of fishery management units and biological population structure can potentially result in a misperception of the productivity and sustainable yield of fish stocks. We used simulation modelling as a tool to compare the perception of productivity, stability, and sustainability of Atlantic cod (Gadus morhua) off New England froman operating model based on the current US management units to a model that more closely reflects the biological complexity of the resource. Two age-structured models were compared: (i) the management unit model, wherein cod were grouped based on the current spatially defined US management areas (Gulf of Maine and Georges Bank), and (ii) the biological unit model, consisting of three genetically defined population components (northern spring spawning, southern winter/spring spawning, and eastern Georges Bank spring-spawning groups). Overall, the regional productivity and maximum sustainable yield of the biological unit model was lower compared with the management unit model. The biological unit model also provided insights on the distribution of productivity in the region, with southern and northern spawning groups being the dominant contributors to the regional spawning-stock biomass and yield and the eastern Georges Bank spawning group being the minority contributor at low to intermediate levels of fishing mortality. The comparison of models revealed that the perception of Atlantic cod derived from the management unit model was of a resource that is more resilient to fishing mortality and not as susceptible to "collapse" as indicated by the biological unit model. For Atlantic cod, one of the main risks of ignoring population structure appears the potential for overexploitation of segments of the population. Consideration of population structure of cod changed our perception of the magnitude and distribution of productivity in the region, suggesting that expectations of sustainable yield of cod in US waters should be reconsidered. © International Council for the Exploration of the Sea 2014. All rights reserved. Source

Holland D.S.,Gulf of Maine Research Institute | Wiersma J.,University of Rhode Island
Marine Policy

Harvest cooperatives were implemented in several US fisheries over the last decade during a period when US law prohibited implementation of any new individual fishery quota (IFQ) systems. Harvest cooperatives provided an alternative to individual quotas as a means to end the race for fish and increase fishery profitability. The prohibition on new IFQ systems in the US was lifted, but harvest cooperatives remain a more feasible and perhaps a superior alternative to IFQs for some fisheries. The New England Fishery Management Council is on the verge of implementing a new management system for the groundfish fishery based on harvest cooperatives known as "sectors". This paper describes the New England sector management system and discusses a number of advantages but also some drawbacks relative to IFQs. It argues that a hybrid of the two approaches could have advantages over either. © 2010 Elsevier Ltd. Source

Andrews A.H.,National Oceanic and Atmospheric Administration | Kerr L.A.,Gulf of Maine Research Institute
Environmental Biology of Fishes

Age validation studies of large shark species using bomb radiocarbon (14C) dating have revealed that the growth of vertebrae can cease in adults. In a previous study of white sharks (Carcharodon carcharias) of the northeastern Pacific Ocean the latest growth material (leading edge of the corpus calcareum) was assigned a known date-of-formation assumed to coincide with the individual’s date of capture. This perspective prevented the assignment of older years of formation (a shift in age) to this material, leading to complicated results and no validated age estimates. A reanalysis of the bomb 14C data, in light of the recent findings for other species, has led to a validated lifespan estimate exceeding 30 years for white sharks of the northeastern Pacific Ocean. © 2014, Springer Science+Business Media Dordrecht. Source

Holland D.S.,Gulf of Maine Research Institute
Ecological Economics

Bycatch is a nearly universal problem for fisheries, and it is increasingly common to place strict limits on allowable bycatch either on individuals or an industry sector. Individual bycatch quotas strengthen individual incentives to avoid bycatch and may reduce the likelihood that the bycatch cap will limit target species catch. However, in cases where bycatch is highly uncertain and variable, individual quotas and markets may be subject to high price variability and may fail to allocate quota efficiently. In some cases such as sea turtles, marine mammals, rare seabird and certain fish species, the allowable take may be less than one per permit holder. There are a number of reasons to believe that a transferable quota market may not function effectively in these cases. I explore the implications of stochasticity and uncertainty of bycatch for valuing quota in an individual bycatch quota system. I explore the degree to which a quota market increases expected profit and reduces individual risk relative to simply having a non-transferable individual bycatch quota, and how pooling approaches and possibly market insurance can be used to reduce financial risk for fishermen associated with uncertain bycatch. © 2010 Elsevier B.V. Source

News Article
Site: http://news.yahoo.com/science/

In this Sept. 2, 2016 photo, Woods Hole Oceanographic Institution engineers Sean Whelan, left, and Patrick Deane release a Slocum glider into the waters south of Martha's Vineyard, Mass. to monitor anticipated changes in the ocean during the passage of tropical storm Hermine. The underwater drones, or gliders as they are known, collect data that scientists say will help them better understand what sustains and strengthens hurricanes and tropical storms. (Ken Kostel/Woods Hole Oceanographic Institution via AP) BOSTON (AP) -- As Hermine worked its way up the East Coast, scientists deployed several underwater drones they say will help them better understand what sustains and strengthens hurricanes and tropical storms — and ultimately better protect life and property. The ocean gliders, as they are called, resemble yellow-winged torpedoes. They were released into the ocean roughly 100 miles offshore at the continental shelf, where at depths of 100 to 300 feet they measured water temperatures, salinity and density before, during and even after the storm. Traditional research aircraft that are flown into the eye of a hurricane to take measurements can't get a read on any of that. "One reason hurricanes are so hard to forecast is that intensity depends on conditions ahead of and below the storm," said Glen Gawarkiewicz, an oceanographer at the Woods Hole Oceanographic Institution in Falmouth, Massachusetts. The robotic gliders, which are remotely controlled from the shore, can delve into the heart of the storm where it's too dangerous or impractical to send people, and then feed real-time information via satellite to scientists safe on land. The gliders have been in use for several years now, but this is the third year of the coordinated program funded by the NOAA office of Oceanic and Atmospheric Research. Gawarkiewicz said the latest deployments will give a "look at the continental shelf system in a more holistic manner." Woods Hole works on the federally funded program in conjunction with the University of Maine, the University of Maryland, Rutgers University and the Gulf of Maine Research Institute. The most important thing the gliders collect is water temperature, an important tool in predicting storm intensity, Gawarkiewicz said. If the storm churns up colder water from the deep ocean, it will decrease in intensity. The data will help forecasters better predict future storms, and perhaps better warn coastal residents when a monster hurricane is about to hit. Scientists hit the jackpot with Hermine. Although it was a relatively weak hurricane and had been downgraded to a tropical storm by the time it reached waters off the Northeast, it moved slowly and lingered in the Atlantic off the New York/New England coast for a few days, giving scientists a wider window in which to gather data. The gliders are still out there, collecting post-storm data that will give scientists a picture of what happens weeks after a hurricane or tropical storm passes through, which can affect future weather. It may take months to fully analyze the Hermine data, but there have already been some surprises, Gawarkiewicz said. For example, the storm drifted farther west than originally predicted, and the data collected may help explain why.

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