Fisheries

winter flounder

lobster

summer flounder (fluke)

bay scallop

longfin squid eggs

Eelgrass, Zostera marina, provides habitat for many commercially valuable species of fish, crustaceans, and mollusks here on Long Island. Many commercially important fish and invertebrates utilize seagrass meadows at some stage, either as a “nursery” during juvenile phases or for a brief break to forage, lay eggs, or evade predators during migrations. Those species of fish and invertebrates not considered commercially valuable may serve as important food sources for the commercial species.

Eelgrass provides many benefits to the fauna that inhabit it, the most profound likely being the “nursery” role. Because eelgrass blades lessen water movement, planktonic fish and invertebrate larvae often settle in eelgrass meadows, and these species likely remain here until they reach a size/age that they can venture to other habitats. The most significant “nursery” function of eelgrass meadows is likely the complex structure that it forms, providing shelter from predators, although increased food availability is expected to contribute to survivorship of juveniles as well. Studies have found that growth rates, of juveniles are greater in seagrass habitats compared to unstructured habitats (Heck et al. 2003).

Fish

Juvenile and adult fish species important to Long Island fisheries that we often see utilizing eelgrass meadows include winter and summer flounder (fluke), porgies, tautog (blackfish), black sea bass, bluefish, striped bass, and northern puffers.  Many of these species are migratory and therefore don’t reside in eelgrass meadows for the entirety of their life cycle, but they do utilize these habitats as a “nursery” during juvenile phases, and many return as adults for food and protection during migrations.  Further studies are needed to evaluate the extent to which these species depend on eelgrass meadows for survival.

Mollusks and Crustaceans

Shellfish including bay scallops and clams benefit from the protection of eelgrass meadows as well as higher concentrations of particulate food. The highest densities of these bivalves have been found along the edges of seagrass beds, likely because the increased food availability here leads to increased growth rates (Bologna and Heck, 1999). Peterson et al. (2001) found no significant difference in predation pressure between the edge and center of eelgrass beds, but found both of these had significantly less predation than non-vegetated habitats. Learn more about Bay Scallops and Shellfish...

Adolescent lobsters burrow in eelgrass for protection and have been known to overwinter in these habitats (Short et al. 2001). Longfin squid eggs are often found attached to eelgrass blades in Long Island Sound. These transient cephalopods are social spawners, laying their eggs in masses. Each capsule is laid by a single female and contains 200 eggs.

 

References:

Bologna PAX and Heck KL. 1999. Differential predation and growth rates of bay scallops within a seagrass habitat. J Exp Mar Biol Ecol 239: 299-314.

Heck KL, Hays CG and Orth RJ. 2003. A critical evaluation of the nursery role hypothesis for seagrass meadows. Mar Ecol Prog Ser 253: 123-136.

Larkum, A.W.D., Orth, R.J., Duarte. C.M. (Editors), 2006. Seagrasses: Biology, Ecology and Conservation. Springer.

Peterson BJ, Thompson KR, Cowan JH and Heck KL. 2001. Comparison of predation pressure in temperate and subtropical seagrass habitats based on chronographic tethering. Mar Ecol Prog Ser 224: 77-85.

Short FT, Matso K, Hoven HM, Whitten J, Burdick DM and Short CA. 2001. Lobster Use of Eelgrass Habitat in the Piscataqua River on the New Hampshire/Maine Border, USA. Estuaries 24(2):277-284.

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