The Hook and Line Survey uses rod and reel gear to sample fish in areas that are difficult to survey using traditional methods such as research trawl nets. These areas include hard seafloor habitats like rocky reefs, boulder fields, and large undersea cliffs and pinnacles. Most of the species targeted by the Hook and Line Survey are rockfish, which are taxonomically classified in the genus Sebastes. Key species of rockfish include bocaccio (S. paucispinis), cowcod (S. levis), greenspotted rockfish (S. chlorostictus), and the vermilion rockfish complex (S. miniatus and S. crocotulus).
We work collaboratively with the local sportfishing industry aboard their boats and visit approximately 200 fixed sites each year over the course of the survey. Survey biologists collect information about the abundance, biology, ecology, and genetics of species that are important to both the sport and commercial fishing industries. Other researchers combine this survey information along with data from many other sources to produce a stock assessment — a single document that summarizes all that we know about the health and biology of a particular species.
In addition to the survey’s primary objective of collecting information to promote the sustainable management of our fisheries, we conduct a variety of supporting research on the ecology and oceanography in the region while the vessels are under charter. We tow a portable camera sled just above the seafloor to collect video so we can learn more about the different types of habitat at our survey sites and what types of fish live there. Click here for more information about our research using the camera sled.
We also lower a CTD (Conductivity-Temperature-Depth) sensor into the water and descend it all the way to the bottom at each site. This special device is outfitted with oceanographic sensors to gather information on the temperature, salinity, dissolved oxygen, chlorophyll, and turbidity of the water at each site from the surface all the way to the seafloor. This information helps us understand how ocean conditions influence the abundance and behavior of fish over time.
Our survey team works with geneticists whose research identifies and uses the tiny differences in DNA between fish species to improve how we assess and manage our fisheries. One application of this genetics research is to conclusively identify a fish to the correct species. For example, there are over 100 different species of rockfish in the genus Sebastes, and several of them can look very similar to one another. The ability to positively distinguish one species from its cryptic pair is a useful tool. Click here for more information on one example of how we use genetics to improve fisheries research and management.
During the 2014 and 2015 Hook and Line Surveys, we added about 80 new sites to the survey’s sampling frame, bringing the total number of sites sampled each year to 200. These new sites are located in the center of the Southern California Bight inside two large areas that have been closed to most sport and commercial bottom fishing since 2001 (see the map of the survey’s 200 fixed sites at right). These areas – known as the Cowcod Conservation Areas - were closed to fishing to help rebuild the bocaccio and cowcod stocks which had become critically overfished. By adding these new sites to the survey, we will be able to better evaluate how these populations respond over time and provide a fuller understanding about the population dynamics of important species in the region as a whole. Click here for more information about research in the Cowcod Conservation Areas.
The Hook and Line Survey will conduct its 14th consecutive field season in 2016. The survey has contributed information to the stock assessments and life history studies of several important species of rockfish including bocaccio, chilipepper (S. goodei), cowcod, greenspotted rockfish, rosy rockfish (S. rosaceus), vermilion rockfish, yelloweye rockfish (S. ruberrimus), and yellowtail rockfish (S. flavidus). Survey data have also been used to track the rebuilding of the overfished bocaccio and cowcod populations, help define the biology of cryptic rockfish species, provide voucher specimens for genetics research and observer training, and support research at universities along the West Coast on the life history of various species of rockfish.
One of the survey's biggest successes is the relationship we have built with our collaborators in the fishing industry. This is one of relatively few ongoing partnerships between scientists and the sportfishing industry, and we have benefited tremendously from the knowledge and perspectives our captains and deckhands have developed during their careers — some of which span more than 40 years on the water. The Hook and Line Survey's design, methods, and gear were all developed with significant input from our industry partners. We look forward to many more years of successful research through this partnership.
The importance of spatial models for estimating the type and strength of density dependence appearing on pp. 1202-1212 of Ecology, vol. 96, May 2015
Patent information about the DNA sampling hook used during the Hook and Line Survey developed by NWFSC researchers.
For more information about the Hook and Line Survey, please contact:
John Harms, Research Fisheries Biologist