River Herring: Status and Threats Overview Karin E. Limburg

1. River Herring: Status and Threats Overview Karin E. Limburg SUNY College of Environmental Science & Forestry, Syracuse, NY

2. Outline of today’s talk: • A bit of river herring biology and ecology • A look at r.h. in the past • The present situation

3. Biology & Ecology Two separate herring species in the subfamily Alosinae – blueback herring (Alosa aestivalis) and alewife (A. pseudoharengus) Closely related – capable of hybridizing Anadromous – spawn in fresh waters in spring Migrate to sea to grow and mature – largely a “big black box” at present Broad geographic ranges

4. River Herring in New York State NYS Canal Authority

5. Part of the lock and canal system on the Mohawk River (NYS Barge Canal). Every time the locks open and close, there are opportunities for fish passage.

6. River herring composed vast fisheries up and down coast (C. Hall will talk about Maine) NMFS

7. State and US fishery statistics

8. Attempting to parse out by species

9. Former strong links betw. inland and marine productivity Today, these links are greatly diminished

10. Current consensus – coast-wide stock assessment completed spring 2012 for ASMFC

11. Source: ASMFC

12. From the stock assessment report: • 57 “Systems” on Atlantic coast • 9 categories of FI &FD data • 54% are blank • Only 26% of remaining have “good” or complete (green) data • Most occurs in NE states River herring Stock Assessment Subcommittee (SASC)

13. US Landings by State NC SC ME MD SASC

14. Reported NAFO landings – large foreign fleet catches in late ’60s – early ’70s SASC

15. For some time, bycatch (incidental catch) in marine fisheries has been suspected to be a large problem…SASC did 1st thorough assessment Photo: Stephen McGowan, Marine PhotoBank Stock assessment looked into current sources of mortality for r.h.

16. Bycatch evaluation

18. Relative abundance data (size of the spawning runs) - A mixed bag. Depends in part on length of dataset. Trends most clear in longer data sets.

19. Mean size of adults, size at age, and amount of repeat spawning is going down

20. Also from the stock assessment report: • mortality rates are higher than most stocks can support • directed fisheries exploitation rates are little to none • therefore, something else is going on (e.g., bycatch, watershed impacts)

21. Recommendations from the stock assessment (some of many) • Determine impacts of bycatch: • Determine “who” is getting caught in bycatch • Determine which stocks are vulnerable to mixed stock fisheries • Reduce mortality! • Monitor success of river restoration efforts • Improve understanding of juvenile requirements

22. River herring distinct population segments Data: E. Palkovacs, E. Argo, D. Hasselman

23. Complementary project under-way – river herring stock discrimination in NYS and rest of coast Sponsored by HRF, thank you! Peeble’s Isl, (Mohawk mouth, rkm 240) Coxsackie (rkm 201) Newburgh (rkm 96) Peconic River Carll’s River Big Fresh Pond Carman’s River

24. 1 mm Mn:Ca Water Lower HR 2009 1.0 Lower HR 2010 0.8 Upper HR 2009 Upper HR 2010 0.6 Tribs 2009 Tribs 2010 0.4 LI 2009 LI 2010 0.2 0.0 -1.00 -0.50 0.00 0.50 1.00 Re-scaled Canonical Variate 2 (34.9%) -0.2 -0.4 -0.6 -0.8 -1.0 Re-scaled Canonical Variate 1 (64.5%) 87/86Sr d18O Ba:Ca Sr:Ca

25. Watershed impacts: dams Small dam on Quassaick Creek  Conowingo Dam (Susquehanna) Holyoke Dam (CT River) 

26. 2000 Maps (top left, clockwise): Dittman et al. unpub.; Hall et al. 2010; Swaney et al. 2006; damsafety.org; Wikipedia

27. 100% 80% Merrimack R. 1st to last dam 60% 1st to 2nd dam 40% 20% 100% 80% Connecticut R. 60% 40% Passage efficiency between dams 20% 100% 80% Susquehanna 60% 40% 20% 0% 1980 1985 1990 1995 2000 2005 2010 2015 Passage efficiency from sea to upstream spawning grounds is not good… Stats for American shad. And where shad cannot go, neither can river herring…unless they’re trucked Brown et al. in revision.

28. Watershed impacts: Urbanization and sprawl growth

29. 1988: Studied 16 tribs, in 4 “reaches” of the estuary: 1st to 9th order

30. 2009: Growth and condition of YOY alewives reduced by urbanized watersheds (R. Monteiro et al. in revision)

31. Endangered Species Act (ESA) listing process Initiated by the NRDC 3 workshops this past summer Decision will be made later this fall or early next year.

32. ? !!

33. This project feeds into a larger project that combines genetic markers of r.h. coast-wide and oto. chem. to ID fish in marine bycatch (“who’s getting caught”)

34. Habitat needs…

35. Habitat Restoration, passage

36. Take-homes: • River herring down around historic lows – is this a critical point? Is depensation occurring? • Efforts really needed to re-build biomass • this means we need to reduce mortality and increase recruitment – need to address both marine and inland concerns

37. Alewives The End!

38. Shad-blueback?? (“shad-back”) Alewife-blueback (“ale-back”) Hybrids found at sea (NMFS fall trawl survey 2011)

40. *** *** *** ** ** *** ** * *** *** SASC

41. Group 1 1984-2010 Group 2 SASC

42. 1984-2010 Group 3 Group 4 SASC

43. Probably due to gregarious behavior as well as use of small systems for spawning, river herring are not as genetically distinct as shad or salmon

44. 1 mm Alewife EAS-60, Cape Cod 10 0.05 8 0.04 6 0.03 Increments Daily increment widths, microns Mn:Ca x 1000 4 0.02 Mn:Ca x 1000 2 0.01 5-pt moving avg of growth 0 0.00 0 25 50 75 100 125 Age (days) YOY alewife otolith from an urbanized Cape Cod watershed (Herring Brook) subject to seasonal hypoxia – with no escape… Limburg, unpub. data