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 Young-of-the-Year Abundances Atlantic Silverside Bay-wide Geometric Mean Catch per Haul

40 35 Atlantic Menhaden 30 Bay-wide Geometric Mean Catch per Haul 25 20 GM 15 10 5 18 0 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 16 14 12 Year 10

GM 8 6 4 Mummichog 2 Bay-wide Geometric Mean Catch per Haul 0 2010 2013 2001 2004 2007 1992 1995 1998 1980 1983 1986 1989 1959 1962 1965 1968 1971 1974 1977

2.5

Year 2.0

1.5

GM 1.0

0.5

Bay Anchovy 0.0 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013 Bay-wide Geometric Mean Catch per Haul

Year

8 7 6 Spottail Shiner 5 Bay-wide Geometric Mean Catch per Haul 4 GM 3 2 3.0 1 2.5 0 2.0 2013 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 1.5 GM 1.0 Year 0.5 0.0 1959 1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 2007 2010 2013

Year Maryland DNR Juvenile Fish Seine Survey 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