Catches in ghost-fishing octopus and fish traps in the northeastern Atlantic Ocean (Algarve, Portugal)

Ghost fishing is the term used to describe the continued capture of fish and other living organisms after a fisherman has lost all control over the gear. Traps may be lost for a variety of reasons including theft, vandalism, abandonment, interactions with other gear, fouling on the bottom (i.e., traps and ropes are caught on rocky substrate), bad weather, and human error (Laist, 1995). Annual trap loss can be as high as 20% to 50% of fished traps in some fisheries (Al-Masroori et al., 2004). Because lost traps can continue to fish for long periods, albeit with decreasing efficiency over time (e.g., Smolowitz, 1978; Breen, 1987, 1990; Guillory, 1993), ghost fishing is a concern in fisheries worldwide.

Interactions between marine mammals and pelagic longline fishing gear in the U.S. Atlantic Ocean between 1992 and 2004

The U.S. East Coast pelagic longline fishery has a history of interactions with marine mammals, where animals are hooked and entangled in longline gear. Pilot whales (Globicephala spp.) and Risso’s dolphin (Grampus griseus) are the primary species that interact with longline gear. Logistic regression was used to assess the environmental and gear characteristics that influence interaction rates. Pilot whale inter-actions were correlated with warm water temperatures, proximity to the shelf break, mainline lengths greater than 20 nautical miles, and damage to swordfish catch. Similarly, Risso’s dolphin interactions were correlated with geographic location, proximity the shelf break, the length of the mainline, and bait type. The incidental bycatch of marine mammals is likely associated with depredation of the commercial catch and is increased by the overlap between marine mammal and target species habitats. Altering gear characteristics and fishery practices may mitigate incidental bycatch and reduce economic losses due to depredation.

Use of genetic data to assess the uncertainty in stock assessments due to the assumed stock structure: the case of albacore (Thunnus alalunga) from the Atlantic Ocean

Stock assessments can be problematic because of uncertainties associated with the data or because of simplified assumptions made when modeling biological processes (Rosenberg and Restrepo, 1995). For example, the common assumption in stock assessments that stocks are homogeneous and discrete (i.e., there is no migration between the stocks) is not necessarily true (Kell et al., 2004a, 2004b).

New information from fish diets on the importance of glassy flying squid (Hyaloteuthis pelagica) (Teuthoidea: Ommastrephidae) in the epipelagic cephalopod community of the tropical Atlantic Ocean

Squids of the family Ommastrephidae are a vital part of marine food webs and support major fisheries around the world. They are widely distributed in the open ocean, where they are among the most abundant in number and biomass of nektonic epipelagic organisms. In turn, seven of the 11 genera of this family (Dosidicus, Illex, Martialia, Nototodarus, Ommastrephes, Sthenoteuthis, and Todarodes) are heavily preyed upon by top marine predators, i.e., birds, mammals, and fish, and currently support fisheries in both neritic and oceanic waters (Roper and Sweeney, 1984; Rodhouse, 1997). Their commercial importance has made the large ommastrephids the target of many scientific investigations and their biology is consequently reasonably well-known (Nigmatullin et al., 2001; Zuyev et al., 2002; Bower and Ichii, 2005). In contrast, much less information is available on the biology and ecological role of the smaller, unexploited species of ommastrephids (e.g., Eucleoteuthis, Hyaloteuthis, Ornithoteuthis, and Todaropsis).

Historical Catches of Humpback Whales, Megaptera novaeangliae, in the North Atlantic Ocean: Estimates of Landings and Removals

Whaling for humpback whales, Megaptera novaeangliae, in the North At- lantic Ocean has occurred in various forms (e.g. for local subsistence, for oil to be sold commercially, using hand harpoons and deck-mounted cannons, using oar-driven open boats and modern powered catcher boats) from the early 1600’s to the present. Several previous attempts to estimate the total numbers of humpback whales removed were considered close to comprehensive, but some uncertainties remained. Moreover, the statistical uncertainty was not consistently presented with the previous estimates. Therefore, we have pursued several avenues of additional data collection and conducted further analyses to close outstanding data gaps and address remaining issues. Our new estimates of landings and total removals of humpback whales from the North Atlantic are 21,476 (SE=214) and 30,842 (SE=655), respectively. These results include statistical uncertainty, reflect new data and improved analysis methods, and take account of some fisheries for which estimates had not been made previously. The new estimates are not sufficiently different from previous ones to resolve the major inconsistencies and discrepancies encountered in efforts to determine the conservation status of humpback whale populations in the North Atlantic.

The Status of Eelgrass, Zostera marina, as Bay Scallop Habitat: Consequences for the Fishery in the Western Atlantic

Zostera marina is a member of a widely distributed genus of seagrasses, all commonly called eelgrass. The reported distribution of eelgrass along the east coast of the United States is from Maine to North Carolina. Eelgrass inhabits a variety of coastal habitats, due in part to its ability to tolerate a wide range of environmental parameters. Eelgrass meadows provide habitat, nurseries, and feeding grounds for a number of commercially and ecologically important species, including the bay scallop, Argopecten irradians. In the early 1930’s, a marine event, termed the “wasting disease,” was responsible for catastrophic declines in eelgrass beds of the coastal waters of North America and Europe, with the virtual elimination of Z. marina meadows in the Atlantic basin. Following eelgrass declines, disastrous losses were documented for bay scallop populations, evidence of the importance of eelgrass in supporting healthy scallop stocks. Today, increased turbidity arising from point and non-point source nutrient loading and sediment runoff are the primary threats to eelgrass along the Atlantic coast and, along with recruitment limitation, are likely reasons for the lack of recovery by eelgrass to pre-1930’s levels. Eelgrass is at a historical low for most of the western Atlantic with uncertain prospects for systematic improvement. However, of all the North American seagrasses, eelgrass has a growth rate and strategy that makes it especially conducive to restoration and several states maintain ongoing mapping, monitoring, and restoration programs to enhance and improve this critical resource. The lack of eelgrass recovery in some areas, coupled with increasing anthropogenic impacts to seagrasses over the last century and heavy fishing pressure on scallops which naturally have erratic annual quantities, all point to a fishery with profound challenges for survival.

Deepwater and Other Sharks of the U.S. Atlantic Ocean Exclusive Economic Zone

Fifty-one deepwater and other shark species of the U.S. Exclusive Economic Zone in the Atlantic Ocean and Gulf of Mexico, which currently are not included in any Federal fishery management plan, are described, with a focus on primary distribution. Many of these shark species are not well known, while others which are more common may be of particular interest. Owing to concerns regarding possible increases in fishing effort for some of these species, as well as possible increases in bycatch rates as other fisheries move farther offshore, it is important that these sharks be considered in marine ecosystem management efforts. This will necessitate a better understanding of their biology and distribution. Primary distribution maps are included, based on geographic information system (GIS) analyses of both published and unpublished data, and a review of the literature. The most recent systematic classification and nomenclature for these species is used.

A Review of Stock Identification of Haddock, Melanogrammus aeglefinus, in the Northwest Atlantic Ocean

Haddock, Melanogrammus aeglefinus, is a principal commercial species distributed throughout the northwest Atlantic Ocean, with major aggregations occurring on Georges Bank and on the Scotian Shelf. This review examines all available information on stock structure of haddock to evaluate the suitability of current stock units and to investigate areas that require further research. Combined information from tag-recapture, demographic, recruitment, meristic, parasitic, and genetic studies provide evidence for the identification of haddock stocks, with major population divisions occurring between New England, Nova Scotia, and Newfoundland waters. Within each of these major divisions a number of discrete stocks appear to exist, although uncertainty remains in the amount of separation found within each region. Research utilizing more recent stock identification techniques should refine and improve our understanding of haddock stock structure in the northwest Atlantic.

The 1996 U.S. Purse Seine Fishery for Tropical Tunas in the Central-Western Pacific Ocean

The U.S. tropical tuna purse seine fleet has fished the central-western Pacific Ocean under the South Pacific Tuna Treaty since 1988. The 1996 fishery was the poorest since the start ofthe Treaty. Fishing effort declined due to the financial collapse of a large fishing enterprise. Catches reached record lows for yellowfin tuna, Thunnus albacares, and skipjack tuna, Katsuwonus pelamis, and continued a declining trend that started in 1995. Catch rates also decreased to the lowest levels since 1991. Whether this declining trend in catch rates is due to reduced availability of fish caused by cyclic ocean environmental changes affecting vulnerability or to reduced abundance from excessive fishing pressure is not yet known and needs to be assessed.