Assessing the potential benthic–pelagic coupling in episodic blue mussel ( Mytilus edulis) settlement events within eelgrass ( Zostera marina) communities

• Published in: Journal of experimental marine biology and ecology 2005-03, Vol.316 (2), p.117-131
• Main Authors: Bologna, Paul A.X., Fetzer, Michele L., McDonnell, Sean, Moody, Erin M.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Asterias; Asterias forbesii; Aureococcus anophagefferens; Benthic–pelagic coupling; Biological and medical sciences; Blue mussel; Callinectes sapidus; Carcinus maenas; Eelgrass; Fundamental and applied biological sciences. Psychology; Libinia; Mytilus edulis; Sea water ecosystems; Synecology; Xanthidae; Zostera marina
• ISSN: 0022-0981; 1879-1697
• DOI: 10.1016/j.jembe.2004.10.009

Coastal marine seagrass ecosystems are important nursery grounds for commercially and recreationally important species, and they serve as key settlement and recruitment sites for other species. We investigated several years (2001–2003) where episodic settlement events of blue mussels ( Mytilus edulis) occurred in Barnegat Bay, NJ, USA. Population assessment indicated that blue mussels settled in eelgrass beds ( Zostera marina) in late spring with peak densities exceeding 170,000 m −2. Based on calculated filtration rates of M. edulis, we determined that for at least 53 days in 2001, the density and size distribution of M. edulis were sufficient to filter the water column volume in excess of twice a day, with maximum calculated filtration rates exceeding 8 m 3 water m −2 day −1. While the settlement event in 2001 was very localized, in 2003, the settlement event was considerably more widespread throughout the bay, with maximum settling densities exceeding 175,000 individuals m −2. Associated with these high densities, maximum calculated filtration rates exceeded 15 m 3 water m −2 day −1. This filtration potential may have impeded the localized development of a brown-tide ( Aureococcus anophagefferens) bloom in 2001, which occurred in other regions of the bay, but the widespread settlement event seen in 2003 may have impeded the development of any brown-tide blooms in Barnegat Bay during that summer. The decline in mussel densities throughout the summer may be a result of elevated water temperatures in this back bay, but at one site, the high settlement of M. edulis was followed by a substantial migration (>40 individuals m −2) of small sea stars ( Asterias forbesii). In 2001, A. forbesii was a significant factor in reducing M. edulis density by the end of the summer at the Barnegat Inlet site and a community level assessment showed significant positive correlations between mussel aggregations and sea star densities ( r=0.68–0.73, P