title: Comparative analysis of different survey methods for monitoring fish assemblages in coastal habitats.
abstract: Coastal ecosystems are among the most productive yet increasingly threatened marine ecosystems worldwide. Particularly vegetated habitats, such as eelgrass (Zostera marina) beds, play important roles in providing key spawning, nursery and foraging habitats for a wide range of fauna. To properly assess changes in coastal ecosystems and manage these critical habitats, it is essential to develop sound monitoring programs for foundation species and associated assemblages. Several survey methods exist, thus understanding how different methods perform is important for survey selection. We compared two common methods for surveying macrofaunal assemblages: beach seine netting and underwater visual census (UVC). We also tested whether assemblages in shallow nearshore habitats commonly sampled by beach seines are similar to those of nearby eelgrass beds often sampled by UVC. Among five estuaries along the Southern Gulf of St. Lawrence, Canada, our results suggest that the two survey methods yield comparable results for species richness, diversity and evenness, yet beach seines yield significantly higher abundance and different species composition. However, sampling nearshore assemblages does not represent those in eelgrass beds despite considerable overlap and close proximity. These results have important implications for how and where macrofaunal assemblages are monitored in coastal ecosystems. Ideally, multiple survey methods and locations should be combined to complement each other in assessing the entire assemblage and full range of changes in coastal ecosystems, thereby better informing coastal zone management.
authors.affiliation: Department of Biology, Dalhousie University , Halifax, Nova Scotia , Canada.
authors.forename: Duncan G L
authors.initials: DG
authors.lastname: Baker
authors.affiliation: Department of Biology, Dalhousie University , Halifax, Nova Scotia , Canada.
authors.forename: Tyler D
authors.initials: TD
authors.lastname: Eddy
authors.affiliation: Department of Biology, Dalhousie University , Halifax, Nova Scotia , Canada.
authors.forename: Reba
authors.initials: R
authors.lastname: McIver
authors.affiliation: Department of Biology, Dalhousie University , Halifax, Nova Scotia , Canada.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Schmidt
authors.affiliation: Fisheries and Oceans, Gulf Fisheries Centre , Moncton, New Brunswick , Canada.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Thériault
authors.affiliation: Fisheries and Oceans, Gulf Fisheries Centre , Moncton, New Brunswick , Canada.
authors.forename: Monica
authors.initials: M
authors.lastname: Boudreau
authors.affiliation: Fisheries and Oceans, Gulf Fisheries Centre, Moncton, New Brunswick, Canada; University of Waterloo, Canadian Rivers Institute, Waterloo, Ontario, Canada.
authors.forename: Simon C
authors.initials: SC
authors.lastname: Courtenay
authors.affiliation: Department of Biology, Dalhousie University , Halifax, Nova Scotia , Canada.
authors.forename: Heike K
authors.initials: HK
authors.lastname: Lotze
keywords: Beach seine; Coastal zone management; Environmental monitoring; Fish assemblage; Survey selection; Underwater visual census (UVC)