Diel vertical migration of copepods and its environmental drivers in subtropical Bahamian blue holesShow others and affiliations
2021 (English)In: Aquatic Ecology, ISSN 1386-2588, E-ISSN 1573-5125, Vol. 55, p. 1157-1169Article in journal (Refereed) Published
Abstract [en]
Diel vertical migration (DVM) is the most common behavioral phenomenon in zooplankton, and numerous studies have evaluated DVM under strong seasonality at higher latitudes. Yet, our understanding of the environmental drivers of DVM at low latitudes, where seasonal variation is less pronounced, remains limited. Therefore, we here examined patterns of vertical distribution in copepods in six subtropical Bahamian blue holes with different food web structure and tested the role of several key environmental variables potentially affecting this behavior. Day and night samplings showed that copepods generally performed DVM, characterized by downward migration to deeper depths during the day and upward migration to surface waters at night. Across all blue holes, the daytime vertical depth distribution of calanoid copepods correlated positively with both predation risk and depth of food resources (Chlorophyll a), but was less affected by ultraviolet radiation (UVR). A potential explanation is that since UVR is a continuous threat across seasons, zooplankton have established photoprotective pigmentation making them less vulnerable to this threat. The copepods also showed a size-structured depth segregation, where larger individuals were found at deeper depths during the day, which further strengthens the suggestion that predation is a major driver of DVM in these systems. Hence, in contrast to studies performed at higher latitudes, we show that despite the constant exposure to UVR, predator avoidance and food availability are the most pronounced drivers of copepod DVM at those low latitudes, suggesting that the main driver of DVM may vary among systems, but also systematically by latitude.
Place, publisher, year, edition, pages
Springer, 2021. Vol. 55, p. 1157-1169
Keywords [en]
Calanoid copepod, Cyclopoid copepod, Vertical distribution, Predation, Food availability, Ultraviolet radiation, Blue hole, Bahamas
National Category
Biological Sciences
Research subject
Biology
Identifiers
URN: urn:nbn:se:kau:diva-81433DOI: 10.1007/s10452-020-09807-4ISI: 000583639100001Scopus ID: 2-s2.0-85094818209OAI: oai:DiVA.org:kau-81433DiVA, id: diva2:1503084
2020-11-232020-11-232025-10-17Bibliographically approved