Effects of shore proximity and depth on the distribution of fish larvae in Bonaire, Dutch Caribbean
A vast majority of marine fish species, both reef and pelagic, are bipartite, meaning that they have a pelagic larval stage distinctly separate from their juvenile and adult stages. The survival of larval fish recruits results in the number of fish that make it to adulthood, which directly correlates to reef and pelagic fish population sizes and diversities that have significant biological and commercial importance. In response to being highly vulnerable to predation in the photic zone of open waters or reefs, fish larvae swim to deeper, darker pelagic waters where they can remain relatively unseen. This study examined whether a greater abundance and diversity of fish larvae would be found further from shore and at deeper depths off the island of Bonaire, Dutch Caribbean. To investigate this, research was conducted at a site close to the fringing reef in front of Kralendijk and a site roughly a kilometer offshore, between Klein Bonaire and Flamingo Airport. At each site, oblique plankton tows were conducted at three depths (≈1.83 m, ≈1.52 m, ≈0.61 m). Samples were analyzed for fish larvae abundance and individual fish larvae were identified to family in order to determine fish larval diversity using Simpson’s Diversity Index. Proximity to shore and depth were shown to have statistical significance on fish larval density. However, the same variables were not shown to have statistical significance on fish larval diversity. This study gives insight into the nocturnal vertical distribution of reef and pelagic fish larvae, which had not been previously studied on Bonaire.