Visual censuses performed during the day underestimate cryptic and nocturnal fish species, including large, carnivorous moray eels. This study developed a census method for morays and used it to determine their density, biomass, distribution and microhabitat use on coral reefs in Barbados. The five species recorded varied in time of highest abundance. Therefore, densities were based on the time when each species was most visible (day or night). Observed densities were corrected for proportion of individuals not visible based on repeated surveys of the same transects. Density (5--6 morays 125m-2 ) and biomass estimates (1--3.7 kg 125 m-2) per site were much higher than those reported in previous censuses and comparable to those of other predatory families. The relative abundance of species varied among sites, and species and size classes also differed in their shelter site use. The higher density and biomass found are believed to be due to the improved method.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.78369 |
| Date | January 2003 |
| Creators | Gilbert, Marianne |
| Contributors | Kramer, D. L. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001982876, proquestno: AAIMQ88204, Theses scanned by UMI/ProQuest. |
Page generated in 0.0017 seconds