Refining the tethering of American oysters (Crassostrea virginica) to measure the effects of two environmental stressors. (February 2018)

• Record Type: Journal Article
• Authors: Poirier, Luke A.; Gilbert, Shane T.C.; St-Hilaire, Sophie; Davidson, Jeff; Cox, Ruth; Quijón, Pedro A.
• Is Part Of: Marine pollution bulletin. Volume 127(2018)
• Page Start: 160
• Page End: 164
• Publication Date: 2018-02
• Subjects: American oyster -- Tethering -- Siltation -- Green crab predation -- Atlantic Canada; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2017.12.007
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Tethering assays, or the physical restraint of test organisms, has been used in the past to measure selected organisms' response to stressors while removing the observer from the experimental setting. Although informative for monitoring and hypothesis testing, these assays often used microfilaments that have been found to be too invasive or prone to biases given their effects on test organisms' behavior. Here, we describe a new variation of tethering using American oysters ( Crassostrea virginica ) and illustrate its use in the study of their mortality rates as a result of two stressors: siltation and predation by a non-indigenous species. Our protocol identified a resistant (non-toxic) glue that could be used to attach oysters to stone slabs, thus partially mimicking the natural cementation of the shell to natural substrates. This variation of tethering was harmless and maintained oysters' body position and natural ability to filter feed. Using tethered oysters in separate two-week field cage experiments, we also show how siltation and predation by a non-indigenous species (the European green crab, Carcinus maenas ), caused a gradual, easily measurable increase in oyster mortality rates. We argue that this variation of tethering is a cost-effective and advantageous way to monitor or test the effects of these and other stressors on oysters and similar species. Highlights: A refined form of tethering is described and tested using American oysters. Attachment of oysters to a stone slab mimics body position and cementation in oysters. This method was used to assess the influence of siltation and predation by invaders. Tethering provided clear, measurable oyster mortality rates in response to both stressors. This refined methodology is suggested for oysters in general and for other stressors.