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- O'Malley, Brian P., et al.
(författare)
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An underwater video system to assess abundance and behavior of epibenthic Mysis
- 2018
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Ingår i: Limnology and Oceanography. - : Wiley. - 1541-5856. ; 16:12, s. 868-880
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Tidskriftsartikel (refereegranskat)abstract
- The application of remote video technologies can provide alternative views of in situ behavior and distribution of aquatic organisms that might be missed with traditional net‐based techniques. We describe a remote benthic video camera system designed to quantify epibenthic density of the macroinvertebrate Mysis diluviana. We deployed the camera multiple times during the day and night at a 60‐m depth site in Lake Champlain and quantified Mysis density from the footage using basic methods and readily available software. Density estimates from the video were on average 43 times higher than concurrent estimates from benthic sled tows, suggesting sleds may be inefficient at sampling mysids. Deployment caused initial scattering of individuals, resulting in low densities immediately after deployment that slowly increased. On some occasions, Mysis densities on video fluctuated greatly over several hours, consistent with organisms that have a patchy distribution on the lake bottom. The camera system provided novel insights on behavior and distribution of Mysis on benthic habitats, demonstrating potential for use as a tool to study partial diel vertical migration and predator–prey interactions.
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| 2. |
- O'Malley, Brian P., et al.
(författare)
-
Evidence for a size-structured explanation of partial diel vertical migration in mysids
- 2018
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Ingår i: Journal of Plankton Research. - : Oxford University Press (OUP). - 0142-7873 .- 1464-3774. ; 40:1, s. 66-76
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Tidskriftsartikel (refereegranskat)abstract
- Mysids are known for benthic-pelagic diel vertical migration (DVM), where the population is benthic by day and pelagic by night. However, historical and recent observations in members of the Mysis relicta complex suggests populations exhibit partial DVM, with some remaining benthic at night. We used pelagic net and benthic sled tows to assess diel habitat use by Mysis diluviana at two stations (60 and 100 m deep) in Lake Champlain, USA, during June-November 2015. At both stations, mysids were on the bottom both day and night, but the extent of pelagic habitat use by Mysis varied by site depth. At 60-m, pelagic densities were an order of magnitude lower during the day compared to at night, indicative of benthic-pelagic DVM. Contrary to expectations, we found no diel difference between pelagic and benthic sled density estimates at 100-m, suggesting an equal number of Mysis are benthic day and night, and an equal number are pelagic-day and night at deeper sites. Mean body length of benthic-caught mysids was greater than pelagic-caught individuals, a pattern that was evident both day and night at 100-m. Our findings indicate Mysis partial DVM is common across seasons and influenced by body size and depth.
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