Forage Fish in Chesapeake Bay: Status, Trends, Science and Monitoring GIT Meeting Chesapeake Biological Lab Solomons, MD 4 December 2013 Chesapeake Bay Watershed Agreement, Draft 11/3/13 Forage Fish Outcome: By 2016 develop a strategy for assessing the forage fish base available as food for predatory species in the Chesapeake Bay. What Are Forage Fish? • Crucial species in food webs • Small, often schooling pelagic Because fish are hatched species at small size, almost all fishes are prey for larger fishes and other predators. But, we • Sardines, anchovies, sand eels, generally don’t consider species krill, herring… that have large adult size and non-schooling behavior as (Lenfest did not include squids) “forage species.” • Feed on plankton and transfer energy to upper trophic levels From Lenfest 2012 Economic Value of Forage Fish Direct value of commercial catch = $5.6 billion Supportive commercial value = $11.3 billion Total global commercial value = $16.9 billion Value in 2006 dollars First ever estimate of total value of forage fish to all fisheries FORAGE FISH DIRECT VALUE FORAGE FISH SUPPORTIVE VALUE Lenfest 2012 Fishes of Chesapeake Bay Striped Bass Spot Atlantic menhaden Mummichog Summer Flounder Bay anchovy Atlantic silverside Atlantic Croaker White Perch Hogchoker Yellow Perch Weakfish American Shad Alewife Cownose Ray Bluefish Blueback Herring Northern Snakehead American Eel Atlantic Sturgeon Blue Catfish Forage Fishes in Chesapeake Bay • Bay Anchovy • Atlantic Menhaden • Atlantic Silverside • Striped Anchovy • Gizzard Shad • Mummichog • YOY Alosines • Spottail Shiner • Other small fishes (gobies, blennies, etc.) Forage fish are valuable as prey Many predators are highly dependent on forage fish... …and decline when forage fish decline. Predators that have a higher proportion of forage fish in their diet generally exhibit greater declines as forage fish abundance decreases. Forage fishes support a diverse spectrum of predators, not only exploitable, piscivorous fishes. Research and monitoring of the predators also is needed. Lenfest 2012 SSC National Workshop IV: EBFM and Forage Fish Issues • Need better ways to estimate forage biomasses • Need better ways to estimate predator demand • Determining M2 is important • Ecosystem forage buffers vs single- species buffers? MAFMC Forage Fish Workshop, April 2013 For consideration • Indicators and reference points • Are there any rules of thumb, e.g., F < M, Biomass threshold, hockey-stick (Restrepo, Lenfest) rules, appropriate F and B levels. • Can predator demand be indexed from stock assessments of predators? • What indices of ecosystem state are available that are indicative of predator demand and prey availability? • Can energetics modeling be useful to estimate demand? • What about ecosystem modeling? Strategic or tactical? Leave one third for the birds Cury et al. 2011 Atlantic Menhaden 2013 2013 2013 2010 2010 2010 2007 2007 2007 2004 2004 2004 2001 2001 2001 1998 1998 1998 1995 1995 1995 1992 1992 1992 1989 1989 1989 1986 1986 Year 1986 Year Year 1983 1983 1983 1980 1980 1980 Mummichog 1977 1977 1977 Shiner Spottail Atlantic Silverside 1974 1974 1974 1971 1971 1971 1968 1968 1968 Haul per Catch Mean Geometric Bay-wide Bay-wide Geometric Mean Catch per Haul per Catch Mean Geometric Bay-wide Bay-wide Geometric Mean Catch per Haul per Catch Mean Geometric Bay-wide 1965 1965 1965 1962 1962 1962 1959 1959 1959 0.0 2.5 2.0 1.5 1.0 0.5 5 0 GM 0.5 0.0 3.0 2.5 2.0 1.5 1.0 40 35 30 25 20 15 10 GM GM 2013 2013 2010 2010 2007 2007 2004 2004 2001 2001 1998 1998 1995 1995 1992 1992 1989 1989 1986 1986 Year Year 1983 1983 1980 1980 Year Abundances Year Bay Anchovy - 1977 1977 Geometric Mean Catch per Haul per Catch Mean Geometric Atlantic Menhaden Atlantic Geometric Mean Catch per Haul per Catch Mean Geometric 1974 1974 the 1971 1971 - 1968 Bay-wide 1968 Bay-wide of 1965 1965 - 1962 1962 1959 1959 2 1 0 6 5 4 3 8 7 2 0 8 6 4 10 GM 18 16 14 12 GM Young Maryland DNR Juvenile Juvenile Seine Survey Maryland Fish DNR VIMS Juvenile Fish Trawl Survey Houde et al. 2006. Progress Report to MD Sea Grant Menhaden: Allocation and EBFM Bluefish Commercial Fishery Predators/Piscivores Striped Bass Weakfish Osprey What is a “Fair” Allocation Plan? Can Humans Cause “Localized Depletion?” Recreational Striped Bass Fishing Research Needs • Abundance Estimates • Predator Demand • Connectivity: Ocean & Estuary • Forecasting Long-term Trends • Energetics and Productivity • Environment and Habitat • Climate Effects Monitoring Needs • Continue Juvenile Index Surveys • Baywide Trawl Survey • Ingress Monitoring • Predators Abundances • Predators Stomach Analyses .