US tab

The Impact of Crown Conch on Intertidal Oyster
Populations in Mosquito Lagoon

By: Casey Craig, Courtney Buck, Chelsea Landau, and Jordan Filipponi
Mentor: Dr. Linda Walters

Abstract

Commercial oyster harvesters in Florida have long complained that the Florida crown conch Melongena corona is in competition with them for harvestable-sized eastern oysters (Crassostrea virginica). Harvesters also suggest that crown conch, rather than overharvesting, has led to a large decline in oyster populations. To determine the role of M. corona on oysters in Mosquito Lagoon, we must first better understand the biology and ecology of M. corona., and to comprehend crown conch biology in Mosquito Lagoon along the east coast of central Florida, we conducted a three-part experiment in Canaveral National Seashore (northern Mosquito Lagoon). Specifically, we designed a field feeding trial to determine prey oyster size preference. To this end, we executed surveys of oyster reefs to gauge the population density of M. corona in Mosquito Lagoon and tracked conch movements in intervals to determine locomotive capabilities. Our results indicate M. corona: 1) was uncommon in Mosquito Lagoon, with the exception of hotspots, 2) did not selectively forage based on tested oyster shell lengths, and 3) moved a mean of 63.5 meters in 24 hours. Based on our abundance data, we estimate that there are 5137 M. corona across 2802 oyster reefs in Mosquito Lagoon (mean: 0.01 conch/m2, with 0.75 conch/m2 in hotspots). More common were thin stripe hermit crabs (Clibanarius vittatus) occupying shells that once housed M. corona. Therefore, it is not likely that M. corona has played a significant role in oyster population declines in Canaveral National Seashore.

KEYWORDS: crown conch, Melongena corona, oyster, Mosquito Lagoon, estuary, overharvesting

Introduction >>