Temporal patterns in the ingress of settlement-stage gray snapper (Lutjanus griseus) and other fishes to Biscayne Bay, Florida, and the Caicos Bank, Turks and Caicos Islands

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)


Marine Biology and Fisheries

First Committee Member

William J. Richards - Committee Chair


Channel nets were moored in Bear Cut, Biscayne Bay, Florida, U.S.A. (BB), and Upper Cut, South Caicos Island, Turks and Caicos Islands (SCI), primarily to identify temporal patterns in the ingress of settlement-stage fishes to Biscayne Bay and the Caicos Bank. Lutjanus (snappers) (BB, SCI) and Albula (bonefish) (SCI) were targeted, while other abundant taxa were also treated. Lutjanus griseus, the most abundant snapper at both sites, was intercepted April through December (BB) and peaked in abundance during new moon periods in the summer (BB, SCI). At BB, new moon catches of L. griseus (and all taxa combined) decreased each year in summer samples (1994 > 1996 > 1997). Albula (SCI) was collected each month sampled, from June to December, with a peak in abundance in early summer. Its ingress pattern was also cyclic on the new moon. At BB, L. griseus was evenly distributed between the surface and subsurface nets, study-wide, and between the two flood tides occurring each night during new moon periods in 1994. Significant differences in depth at ingress were found for nine abundant taxa (BB), five for the surface and four for the subsurface net. Significantly greater catch on the first nighttime flood tide was found for four families. Ingress of L. griseus (BB, SCI) and Albula (SCI) occurred during multiple hours within the first nighttime flood tide on several dates when net(s) were cleared hourly. Lutjanus griseus (BB) was present in summer day samples, in low numbers, during new and quarter moon periods when catches were typically high at night. Ingress of L. griseus (BB, SCI) and Albula (SCI) was significantly associated with nights having two to four hours of dark flood tide (middle category) and the lowest lunar index values (i.e., per cent of moon disc illuminated times hours of nighttime flood tide). Ingress of L. griseus (BB) was significantly associated with nights having weak cross-shelf winds and weak along-shelf winds from the north. Timing, depth, and environmental conditions at ingress of settlement-stage fishes at BB and SCI suggested that larval behavior plays an important role in arrival to nurseries.


Biology, Ecology; Biology, Oceanography; Biology, Zoology; Agriculture, Fisheries and Aquaculture

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