Abstract
Diaseris distorta is a free-living fungiid coral that typically inhabits dense rhodolith beds in the SW Gulf of California where they are often overlooked in this atypical coral habitat. Diaseris distorta ranges throughout the Indo-West Pacific, however the study site at Isla Catalana is its northern-most limit within the Eastern Pacific. On four dates, June 2008, November 2009, July 2010, and August 2014, population density and mean size were documented. Each survey obtained 30 randomly placed ½ x ½ meter photo quadrats. Live coral presence in each quadrat was quantified using CPCe software, then analyzed for differences using a Kruskal Wallis test followed by a Tukey a posteriori test. Coral cover significantly increased (Tukey Test, p<0.05) from 2008 through 2014. In 2008 there was 0.98% coral cover that increased to 3.04% in 2014, a 310% increase over a 6 year period. Also, there was a significant decrease (Tukey Test, p<0.05) in coral size over this period. The size of coral individuals changed from 1.63 cm2 to 1.33 cm2 , a decrease of 19%. Thus, increased cover was due to population growth rather than increased coral size. These results are associated with improving (warmer) conditions at this northern limit of coral distribution, consistent with other observations of increased coral populations at higher latitudes. Increased coral cover has important ecological benefits by providing additional carbonate structure, creating habitats for associated organisms such as invertebrates and fish. This information is useful for National Park personnel to better manage this valuable resource.
Faculty Sponsors
Joshua Feingold, Ph.D.
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-10-2015 1:00 PM
End Date
4-10-2015 5:30 PM
Changes in Coral Cover (Diaseris distorta) at Isla Catalana, Gulf of California, Mexico
Alvin Sherman Library
Diaseris distorta is a free-living fungiid coral that typically inhabits dense rhodolith beds in the SW Gulf of California where they are often overlooked in this atypical coral habitat. Diaseris distorta ranges throughout the Indo-West Pacific, however the study site at Isla Catalana is its northern-most limit within the Eastern Pacific. On four dates, June 2008, November 2009, July 2010, and August 2014, population density and mean size were documented. Each survey obtained 30 randomly placed ½ x ½ meter photo quadrats. Live coral presence in each quadrat was quantified using CPCe software, then analyzed for differences using a Kruskal Wallis test followed by a Tukey a posteriori test. Coral cover significantly increased (Tukey Test, p<0.05) from 2008 through 2014. In 2008 there was 0.98% coral cover that increased to 3.04% in 2014, a 310% increase over a 6 year period. Also, there was a significant decrease (Tukey Test, p<0.05) in coral size over this period. The size of coral individuals changed from 1.63 cm2 to 1.33 cm2 , a decrease of 19%. Thus, increased cover was due to population growth rather than increased coral size. These results are associated with improving (warmer) conditions at this northern limit of coral distribution, consistent with other observations of increased coral populations at higher latitudes. Increased coral cover has important ecological benefits by providing additional carbonate structure, creating habitats for associated organisms such as invertebrates and fish. This information is useful for National Park personnel to better manage this valuable resource.
