Mysid shrimp dynamics in relation to abiotic and biotic factors in the coastal lagoons of Maryland, Mid-West Atlantic, USA

ABSTRACT

The distribution and densities of two mysid species, Neomysis americana and Americamysis bahia in the coastal lagoons of Maryland were investigated using data collected monthly from March 2012 to December 2013. Mysid density was higher in the northern than southern bays in 2013 for Americamysis (P = 0.043) and Neomysis (P = 0.004). Neomysis americana density was inversely correlated with temperature (P < 0.00001) and salinity (P < 0.01), but positively correlated with water depth in 2012 (P < 0.01). In the spring, total mysid and Neomysis densities (nos. m⁻² ± S.E) were negatively related to the catch-per-unit effort (CPUE ± S.E) of fish predators (r = −0.40, −0.81; P = 0.051, 0.002, respectively). Mysid density was higher in winter (March, 1.3 ± 0.8 and spring, May, 1.4 ± 1.3) 2012, when the CPUE of bay anchovy (Anchoa mitchilli) was relatively low (April: 5.8 ± 2.3; and May: 11.9 ± 4.5, 2012), than during summer (August, 0.003 ± 0.002 nos. m⁻²), when fish CPUE was relatively high (191.7 ± 66.5). The observed seasonal patterns of mysid and fish densities, supported by the fact that mysids comprise 53–97% by weight of the diet of some of the abundant fish species in the bays, suggests a top-down control of mysids by fish predation. However, summer high temperatures in the bays exceeded 22°C, at which juveniles of N. americana have been reported to suffer high mortality, and perhaps contributed to the lower density of mysids in the summer.

SUBJECT EDITOR:

• Audrey Geffen

KEYWORDS:

• Distribution
• dynamics
• mysids
• Maryland coastal lagoons
• Mysidae

Acknowledgements

This study was supported by the US National Science Foundation (NSF) under Grant (# 1036586) to the CREST – Center for the Integrated Study of Coastal Ecosystem Processes and Dynamics; and National Oceanic and Atmospheric Administration (NOAA) Educational Partnership Program (EPP) under Grant (# NA11SEC4810002) at the University of Maryland Eastern Shore. We thank Captain Chris Daniel for assistance with field sampling. Fish abundance data were provided by Steve Doctor, Maryland Department of Natural Resources (MD DNR).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Science Foundation under Grant (# 1036586) to the CREST – Center for the Integrated Study of Coastal Ecosystem Processes and Dynamics; and National Oceanic and Atmospheric Administration under Grant (# NA11SEC4810002) at the University of Maryland Eastern Shore.