“It is one of the reasons why the Cayman Islands, and other fisheries jurisdictions around the world, have closed and open seasons, along with bag and size limits, for marine life that is at risk of being overfished.” The Cayman Island government also enacted size and daily count limits during the now-limited fishing season, and spear-fishing for Nassau groupers was prohibited altogether.
“We developed a unique approach for monitoring these populations... a combination of using mark and recapture tagging techniques to track the proportion of tagged fish, and video transects to count fish across the aggregation,” explains Brice Segment, associate professor and ecologist at Scripts. The team shared their data on the grouper aggregations with the Cayman Islands’ local communities and discussed next steps.
A previous version of this article erroneously said the Cayman Islands Department of Energy was involved in this project. A previous version of this article erroneously said whale sharks and mantas feed on Cayman grouper eggs.
Liz covers marine biology, ecology, and oceanography for Forbes Science and works as an environmental consultant in Northern California. … Read More Liz covers marine biology, ecology, and oceanography for Forbes Science and works as an environmental consultant in Northern California.
The research published in Pas covers work conducted in Cayman waters over 15 years aimed at recovering the collapsed stocks of Nassau grouper. The authors of the important peer-reviewed work said that the Nassau grouper “have undergone a remarkable recovery”, which is due to the implementation of deliberate “science-based conservation strategies”.
As a result, Goliath grouper (the continental U.S. distinct population segment) was removed from the species of concern list (71 FR 61022). Scientists from our Southeast Fisheries Science Center are working to understand the changes that have occurred in coral reef ecosystems following the loss of top predators, such as groupers.
From 1997-2005, our researchers collaborated with Florida State University's Institute for Fishery Resource Ecology (Dr. Chris Koenig and Dr. Felicia Coleman) to monitor the status and recovery of Goliath grouper. This Goliath grouper research program investigated juvenile and adult Jewish abundance, distribution and migration patterns; their age and growth; and their habitat utilization.
With the help of Don Maria we have tagged over 1,000 adult Jewish and have observed aggregations of Goliath grouper in both the Gulf of Mexico and more recently, the South Atlantic. Posters created by the Center of Marine Conservation help disseminate information about our project and its requirements, highlighting our tagging study and the morphology of Goliath grouper.
Given that these groupers were afforded protected status, researchers worked to utilize and develop novel non-lethal techniques to procure and analyze biological samples for life history information. Researchers have also determined that soft dorsal rays hold promise for aging older fish (Marie et al., 2008).
These casualties, resulting from red tide, gave our biologists a unique opportunity to collect a multitude of biological samples, without having to sacrifice healthy animals. From these decomposing carcasses, biologists were able to record length for use in an age/length relationship, and were able to extract monoliths and remove dorsal spines and rays for comparison of hard parts in age and growth analysis.
Tissue samples were also removed and sent to the Florida Marine Research Institute, so they could evaluate the level of red tide toxin. The sampling trip gave these biologists an opportunity to educate the curious beach goers about red tide and Goliath grouper (a few of which had been misidentified as baby manatees).
Attempts to evaluate the data needed to assess the status of these depleted stocks and develop rebuilding plans present unique challenges. In 2010, the Florida Fish and Wildlife Conservation Commission and NOAA Fisheries convened a benchmark Goliath grouper assessment for the continental U.S. population.
This project would not have been possible without ongoing collaboration with researchers from Florida State University, Everglades National Park, and the recreational fishing and SCUBA diving communities. Gag grouper will close to recreational harvest in Gulf state and federal waters Jan. 1, 2021.
For gag grouper, state waters off Franklin, Weibull, Taylor and Jefferson counties will reopen to harvest April 1 through June 30 and Sept. 1 through Dec. 31. In the Atlantic and state waters of Monroe County, the grouper closure ends April 30, and harvest will reopen May 1.
The protection will require agencies that fund or permit projects in the grouper ’s habitat to consult with the Service to ensure the area is not damaged. In 2016 the National Oceanic Atmospheric Administration listed the grouper as threatened under the Endangered Species Act in response to a scientific petition from Wilder Guardians.
Poor water quality and increased sedimentation due to land-development practices threaten both coral and macro algae that are important resources during the grouper ’s various life stages. The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.
Guardian has offices in Arizona, Colorado, Idaho, Montana, New Mexico, Oregon, and Washington, and over 278,000 members and supporters worldwide. Our mission is to protect South Florida’s watershed through citizen engagement and community action, ensuring dimmable, drinkable, fishable, water for all.
“Normally, Nassau grouper are relatively solitary, and tend to be hard to catch,” said Lynn Waterhouse, a research biologist at Chicago’s John G. Shed Aquarium and former Scripts Oceanography student. Scripts Institution researchers jointly published their study in the journal Proceedings of the National Academy of Sciences with researchers and scientists from Oregon State University, the Grouper Moon Project, the Cayman Islands Department of Environment and the citizen conservation group Reef Environmental Education Foundation.
Scripts Oceanography Researchers Document Conservation Efforts for Nassau Grouper was last modified: January 6th, 2020 by Christine Hard Many reef fish species that come together in large numbers to spawn are at increased risk of overfishing during such aggregations.
Lynn Waterhouse, Brice Segment, and colleagues analyzed data collected from 2005 to 2018 to determine the effect of governmental fishery management on two populations of Nassau grouper in the Cayman Islands whose breeding areas had been closed seasonally or from which the catch had been limited. According to the authors, seasonal and spatial closures can lead to conservation success in rebuilding populations of aggregation-based fisheries.
Article # 19-17132: Recovery of critically endangered Nassau grouper (Epimetheus stratus) in the Cayman Islands following targeted conservation actions,” by Lynn Waterhouse et al. Scientific products stemming from the project aim to support science-informed policies that will facilitate healthy grouper fisheries in the Cayman Islands in the coming years, while maintaining the Cayman Islands’ global leadership in collaborative tropical fisheries research and management.
Since 2001, REEF and our collaborators have published several scientific papers sharing results from the research. The study used a two-pronged approach that included tagging and video census data for monitoring and counting Nassau Grouper populations in an effort to more accurately estimate annual numbers of fish in the population, and thus provide insight into the effects of ongoing conservation efforts.
When multiple sound-producing species inhabit an area, the detection range may decrease and limit call function. Acoustic partitioning, the separation of calls in time, space, or spectral frequency, can minimize interference among species and provide information about fish behavior and ecology, including possible response to increasing anthropogenic noise.
Results indicate separation in space and time between species calls, which aids in acoustic partitioning. When this separation did not occur, unique call structures were present, which may aid in effective interspecies communication.
This work was presented at the OCEANS19 meeting, and was a result of research done as part of the Grouper Moon Project. Their sounds can be used to monitor these fish and may be a means to estimate abundance if parameters such as source levels, detection probabilities, and cue rates are known.
During the week of Nassau Grouper spawning in February 2017, a passive acoustic array was deployed off Little Cayman in the Cayman Islands to study the temporal and spatial dynamics of spawning aggregations of Nassau Grouper and Red Hind, and measure the source levels of the sounds produced by all four species. In 2014, we tested the use of a split-beam echo sounder as a tool for surveying the abundance and size of fish at the aggregation site; the results of the study are detailed in this peer-reviewed paper.
Like many places throughout the Caribbean, Nassau Grouper spawning aggregations in the US Virgin Islands were overfished until their disappearance in the 1970s and 1980s. In the early 2000s, however, Nassau Grouper were found gathering at Grammar Bank, SVI, a despotic coral reef adjacent to one of the extinct aggregation sites, and regulatory protective measures were implemented to protect this fledgling aggregation.
The authors of this study addressed two objectives: 1) which factors (local vs. external recruitment) are important in shaping recovery of the SVI spawning aggregations, and 2) the impact of severe past overfishing on the genetic structure of the Germanic Bank aggregation. These collective results suggest that external recruitment is an important driver of the SVI spawning aggregation recovery.
The authors obtained genetic tissue samples from 620 Nassau Grouper from 19 sites across 9 countries, including the Cayman Islands. They found evidence for strong genetic differentiation among Nassau Grouper subpopulations throughout the Caribbean.
These results suggest that, despite a lack of physical barriers, Nassau grouper form multiple distinct subpopulations in the Caribbean Sea. These findings highlight the importance of conservation initiatives such at REEF's Grouper Moon programs in the Cayman Islands.
This paper is part of the larger body of genetic research being conducted on Nassau Grouper in the Caribbean. Nassau Grouper (Epimetheus stratus) were historically one of the most important shallow water fisheries in the Caribbean, yet now are rarely taken.
Although normally solitary, during the winter full moon Nassau grouper attend aggregations at spawning site to reproduce. These topics were explored during a presentation given by Grouper Moon researchers at the 2007 Gulf and Caribbean Fisheries Institute conference.
They also discussed critical research needs in the ongoing effort to identify prudent conservation measures for this species, including: habitat capacity, dispensation, and recruitment variability. In 2006, researchers from University of North Carolina Wilmington collaborated with Grouper Moon Project researchers from REEF and Cayman Island Department of Environment to conduct mobile hydro acoustic surveys on the Little Cayman spawning aggregation site.
The goal of the study was to determine the utility of this emerging technology to assist in the estimation of density, spatial extent, and total abundance of a Nassau grouper. This paper provides an overview of the acoustic tagging project that was initiated on Little Cayman Island in 2005.
The project aims to better understand the sphere of influence that a spawning aggregation has on the island's population of Nassau grouper, as well the impact of harvest protections on local fish densities. The seasonal fishing ban on endangered Nassau grouper spawning aggregation sites in the Cayman Islands, which was set to expire at the end of this month, has been extended for another eight years.
The protections, which were initially enacted in 2003 and included an 8-year sunset clause, prohibit fishing for the species at spawning aggregation sites between November and March (the reproductive season). Our research has focused on the west end aggregation site on Little Cayman, which supports one of the last great reproductive populations of this endangered species.
REEF is extremely proud of our involvement in the Grouper Moon Project, and we look forward to similar conservation victories in the years to come. If you haven't yet donated during our Winter Fundraising Campaign, please consider making a generous gift to help REEF continue programs like the Grouper Moon Project.
It has been supported in part by the Len fest Ocean Program, the Disney Wildlife Conservation Fund, the NOAA International Coral Reef Conservation Program, Southern Cross Club, Little Cayman Beach Resort, Peter Hillenbrand, and REEF member contributions.