Photo: Courtesy of SHRMP Science Team and NURTEC at
University of Connecticut
Cusk (Brosme brosme) are a National Marine Fisheries Service (NMFS) "species of concern," as well as a "candidate species" under the Endangered Species Act (ESA) as we are currently conducting a status review on the species. We are also involved in various proactive conservation initiatives described below to obtain more information on this data poor species to assess its status and further conservation efforts. These initiatives involve cooperative efforts with industry, scientists, and other partners to learn more about cusk.
In December 2011, a 2-day workshop on "Proactive Conservation Planning for Northwest Atlantic Cusk" was held. This workshop was conducted at our request and with funding from our program, and coordinated by the Gulf of Maine Research Institute (GMRI). It was designed to provide a forum for the exchange of information on cusk and its habitat, as well as methods to mitigate and reduce bycatch impacts to aid in the conservation of this species. A wide range of participants with backgrounds in science, management and commercial and recreational fishing were invited to share information and gain a better understanding of cusk in the Gulf of Maine.
Climate Change Assessment
We have been working with staff from the NMFS Northeast Fisheries Science Center, NOAA's Office of Oceanic and Atmospheric Research Geophysical Fluid Dynamics Laboratory and Earth System Research Laboratory, the U.S. Environmental Protection Agency, and the University of Connecticut to understand the potential effects of climate change on cusk. The goal of the project was to gather information on the potential impacts of climate change on the species in U.S. Atlantic and Canadian shelf waters. The results of this study were recently published.
Cusk Barotrauma Research
In order to address an existing data gap for cusk, we provided funding for a preliminary study to test the experimental protocol for assessing the impacts of barotrauma on the survival rates of discarded cusk in the lobster trap fishery. Barotrauma was a topic of discussion at the December 2011 Cusk Workshop (see summary above), and identified as an area for further research. The University of Maine was contracted to conduct this study and has been coordinating with Maine Department of Marine Resources and Maine lobstermen. Experimental design and protocol development and testing were started in the spring of 2013. Nine lobstermen from South Bristol, Booth Bay Harbor, and Jonesport have currently volunteered to record catch data on cusk incidentally caught in lobster traps while fishing offshore. Lobster traps are being tested as a mechanism for re-pressurization of incidentally caught cusk. Rapid surfacing of cusk which are bottom dwellers causes them to become positively buoyant. Discarded cusk often will float at the surface making them vulnerable to predators. To increase survivability and aid in re-pressurization this study is placing cusk in the front part of the trap or the "kitchen" to be redeployed with the trap. Participating lobstermen have reported success in cusk surviving re-pressurization via traps. Traps with cusk left in for re-pressurization are marked, and lobstermen have been reporting no signs of the cusk in the trap or rehauling live cusk in the same traps. Live cusk are re-pressurized until they are no longer present in the traps. Signs of barotrauma can be both internal and external; physical symptoms include everted stomach (e.g., stomach extends out of the mouth of the fish), "bug eyes", bubbles on the eyes, and skin blistering. Occurrence of physical symptoms is not an indication of survival, but time at surface and temperature are thought to be the biggest indicators of survival. Observations and information collected to date indicate that cusk are surviving re-pressurization after demonstrating some of the visible external signs of barotrauma noted above. Lobstermen report having seen all physical signs of barotrauma with the extent varying depending on depth. The information and protocol developed and tested in this study will be used to target future cusk barotrauma research in the area pending available funds. A detailed report will be posted when it becomes available.
Data-Poor Species Survey
We coordinated with the Northeast Fisheries Science Center on the development of a bottom longline survey for stocks associated with complex rocky habitat in the western and central Gulf of Maine, including several data poor stocks that are also ESA species of concern. The Northeast Fisheries Science Center was awarded funds for the study through a NMFS FY13 Cooperative Research Solicitation. The study will focus on areas of complex rocky habitat that are not sampled by mobile trawl gear and will address concerns about the catchability of specific species collected during bottom trawl surveys for important groundfish stocks, and will immediately enhance data collection for several data poor stocks and species of concern that are specifically associated with rocky habitat. Data from the survey will provide critical information to assist in conservation and fill-in gaps in life history information for these species. Additional information will be posted on this site when it becomes available.