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Seasonal closures of spawning aggregation sites does not guarantee population recovery: Anthony R. Marshak 1 and Richard S. Appeldoorn 2 1 University of.

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Presentation on theme: "Seasonal closures of spawning aggregation sites does not guarantee population recovery: Anthony R. Marshak 1 and Richard S. Appeldoorn 2 1 University of."— Presentation transcript:

1 Seasonal closures of spawning aggregation sites does not guarantee population recovery: Anthony R. Marshak 1 and Richard S. Appeldoorn 2 1 University of South Alabama/Dauphin Island Sea Lab 2 University of Puerto Rico – Recinto de Mayagüez An assessment of red hind MPAs in Puerto Rico

2 Red Red Hind (Epinephelus guttatus) One of Puerto Rico’s most important commercial and recreational fishes One of Puerto Rico’s most important commercial and recreational fishes Fished up to ~80 m primarily by: Fished up to ~80 m primarily by: Hook-and-line Hook-and-line Fish trap Fish trap Spearfishing with SCUBA Spearfishing with SCUBA Like many groupers, red hind are characterized by: Like many groupers, red hind are characterized by: Long lifespans (>15 years) Long lifespans (>15 years) Slow growth Slow growth Protogynous sexual strategy (Female  Male) Protogynous sexual strategy (Female  Male) Short-term annual spawning aggregations Short-term annual spawning aggregations

3 Puerto Rico Red Hind Landings Recent grouper landings within PR have been much lower than in previous years. Recent grouper landings within PR have been much lower than in previous years. More recently, red hind has become the most frequently captured grouper species in Puerto Rico (Matos-Caraballo et al. 2006). More recently, red hind has become the most frequently captured grouper species in Puerto Rico (Matos-Caraballo et al. 2006). Historically, a major component of landings from Puerto Rico W insular platform spawning aggregations. Historically, a major component of landings from Puerto Rico W insular platform spawning aggregations. Total landings of groupers reported in Puerto Rico during 1971-1995 (Matos-Caraballo, 1997). Total landings of red hind reported in Puerto Rico during 1988-2005 (PR Dept. Natural Resources).

4 Spawning Aggregations (SPAGs) Spawning aggregation: Spawning aggregation: “A group of conspecific fish gathered for the purpose of spawning, with fish densities or numbers significantly higher than those found in the area of aggregation during the non- reproductive periods.” (Domeier and Colin, 1997) “A group of conspecific fish gathered for the purpose of spawning, with fish densities or numbers significantly higher than those found in the area of aggregation during the non- reproductive periods.” (Domeier and Colin, 1997) Red hind short-term annual SPAGs: Red hind short-term annual SPAGs: Found along the edge of insular platforms in deeper waters Found along the edge of insular platforms in deeper waters Migrations Migrations Reproductive benefits of SPAGs overshadowed by historical targeting, due to their predictability in space and time Reproductive benefits of SPAGs overshadowed by historical targeting, due to their predictability in space and time

5 Previous studies have shown the population benefits of closing red hind spawning aggregation sites to fishing in the U.S. Virgin Islands “By 1988, the average length of red hind had greatly decreased to 295 mm, and the sex ratio was extremely skewed to 15 females per male, suggesting a heavily fished stock. In 1990, a spawning aggregation closure was implemented.” Spawning Aggregations - Protection “By 1997, average size of red hind had increased to 395 mm and sex ratio had shifted to 4 females per male.” * From Nemeth, 2005 “…the maximum total length of male red hind increased by nearly 7 cm [five years] following permanent closure.” “Average density and biomass of spawning red hind increased by over 60% following permanent closure, whereas maximum spawning density more than doubled.” Looks Promising! “The Red Hind Bank Marine Conservation District was closed permanently in 1999.”

6 Spawning Aggregations – Puerto Rico Three spawning aggregation sites have been identified within the EEZ off the west coast of Puerto Rico: Three spawning aggregation sites have been identified within the EEZ off the west coast of Puerto Rico: Tourmaline (seasonally closed as of 1993) Tourmaline (seasonally closed as of 1993) Abrir La Sierra (seasonally closed as of 1996) Abrir La Sierra (seasonally closed as of 1996) Bajo de Cico (seasonally closed as of 1996) Bajo de Cico (seasonally closed as of 1996) Annual closures during red hind spawning from Dec 1 – Feb 28. Annual closures during red hind spawning from Dec 1 – Feb 28. Biomass buildup/ speculated spawning activity in open period Biomass buildup/ speculated spawning activity in open period No full comprehensive study yet to assess the effectiveness of the enacted closures No full comprehensive study yet to assess the effectiveness of the enacted closures Set out to evaluate responses in the stock prior to and following enactment Set out to evaluate responses in the stock prior to and following enactment West coast of Puerto Rico and insular platform up to 100 m

7 Datasets Fishery-independent data Fishery-independent data SEAMAP-C database (1988/89–2005/06 project years) SEAMAP-C database (1988/89–2005/06 project years) Samples the west coast of Puerto Rico to collect standardized information on reef fishes Samples the west coast of Puerto Rico to collect standardized information on reef fishes Hook-and-line and trap sampling at daily 2x2 nautical mile stations Hook-and-line and trap sampling at daily 2x2 nautical mile stations Fishery-dependent data Cabo Rojo- Mayaguez Municipalities Fishery-dependent data Cabo Rojo- Mayaguez Municipalities DNER-FRL Red Hind Commercial Landings Data (1988-2005) DNER-FRL Red Hind Commercial Landings Data (1988-2005) DNER-FRL Port-Sampled Red Hind Biostatistical Length Data (1988-2005) DNER-FRL Port-Sampled Red Hind Biostatistical Length Data (1988-2005)

8 Fishery-Independent Data Quantified: Quantified: Catch per Unit of Effort (CPUE) Catch per Unit of Effort (CPUE) Total kg red hind per day fished Total kg red hind per day fished Length-frequency distributions Length-frequency distributions Sex trends Sex trends Measured per project year and spawning period (Dec-Mar) Measured per project year and spawning period (Dec-Mar) Coast-wide Coast-wide Independently within Abrir La Sierra, Bajo de Cico, and Tourmaline Independently within Abrir La Sierra, Bajo de Cico, and Tourmaline Cabo Rojo Mayagüez

9 Red Hind Average Catch Per Unit Effort - Coast-Wide Kruskal-Wallis test (p<<0.001) Nemenyi pair-wise comparisons 1997/98 – Initial increase in project year and spawning period CPUE 1997/98 – Initial increase in project year and spawning period CPUE Declines in later years, especially spawning period CPUE Declines in later years, especially spawning period CPUE Project year CPUE > spawning period CPUE Project year CPUE > spawning period CPUE

10 Red Hind Average CPUE - Seasonally Protected Sites

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12 Red Hind Average Length - Coast-Wide Kruskal-Wallis test (p<<0.001) Nemenyi pair-wise comparisons Significant declines in average length prior to the enactment of closures Significant declines in average length prior to the enactment of closures Marginal increases initially following enactment Marginal increases initially following enactment Significant increases in later years Significant increases in later years

13 1988/89 – Already signs of overfishing, but more recruits, larger females 1988/89 – Already signs of overfishing, but more recruits, larger females 1994/95 – Smaller females and males; few remaining cohorts 1994/95 – Smaller females and males; few remaining cohorts Red Hind Length Frequencies - Coast-Wide

14 1997/98 – Fewer recruits, but increases in age 5-7 individuals 1997/98 – Fewer recruits, but increases in age 5-7 individuals 2005/06 – Mostly few remaining larger females; recruitment limitation? 2005/06 – Mostly few remaining larger females; recruitment limitation? Red Hind Length Frequencies - Coast-Wide

15 Fishery-dependent landings data Cabo Rojo-Mayaguez Kruskal-Wallis test (p<<0.001) Nemenyi pair-wise comparisons Decreased nominal CPUE prior to enactment of closures Decreased nominal CPUE prior to enactment of closures Little increase in CPUE following enactment, but trend maintained Little increase in CPUE following enactment, but trend maintained Small increase in CPUE in later years Small increase in CPUE in later years

16 Fishery-dependent biostatistical length data Cabo Rojo- Mayaguez Kruskal-Wallis test (p<<0.001) Nemenyi pair-wise comparisons Increases in average length over time Increases in average length over time Similar length-frequency patterns, with limited incoming recruits Similar length-frequency patterns, with limited incoming recruits

17 Conclusions The results suggest that the closures initially limited further rapid decline of the Puerto Rico red hind stock. The results suggest that the closures initially limited further rapid decline of the Puerto Rico red hind stock. However, the stock continues to remain in poor form However, the stock continues to remain in poor form Continued fishing in protected areas, increased fishing pressure within previously under-targeted platform regions, and poor enforcement of regulations have inhibited the long term effectiveness of the closures. Continued fishing in protected areas, increased fishing pressure within previously under-targeted platform regions, and poor enforcement of regulations have inhibited the long term effectiveness of the closures.

18 Within the USVI, the Red Hind Bank Marine Conservation District is no further offshore than the three protected areas and alternative aggregations in Puerto Rico, but: Within the USVI, the Red Hind Bank Marine Conservation District is no further offshore than the three protected areas and alternative aggregations in Puerto Rico, but: Lesser available habitat for red hind outside the MCD Lesser available habitat for red hind outside the MCD Increased monitoring of aggregations Increased monitoring of aggregations Rougher conditions than along leeward PR=less fishing intensity Rougher conditions than along leeward PR=less fishing intensity Therefore, a more substantial proportion of the USVI population has remained protected from fishing, as compared to that observed in Puerto Rico. Therefore, a more substantial proportion of the USVI population has remained protected from fishing, as compared to that observed in Puerto Rico.

19 Conclusions The findings suggest that the recovery of red hind in Puerto Rico may be possible, but stock rebuilding will require: The findings suggest that the recovery of red hind in Puerto Rico may be possible, but stock rebuilding will require: Longer time frames Longer time frames Additional restrictions on fishing pressure Additional restrictions on fishing pressure 2004 state waters ban on red hind fishing during spawning season 2004 state waters ban on red hind fishing during spawning season 2007 island-wide spawning season prohibition within all state and western federal waters 2007 island-wide spawning season prohibition within all state and western federal waters Stricter enforcement of regulations Stricter enforcement of regulations Continued monitoring, more complete protection of the stock, and increased public cooperation will hopefully work towards saving and restoring red hind in Puerto Rico Continued monitoring, more complete protection of the stock, and increased public cooperation will hopefully work towards saving and restoring red hind in Puerto Rico

20 Acknowledgements Puerto Rico Dept. Natural and Environmental Resources Fisheries Research Laboratory Staff Puerto Rico Dept. Natural and Environmental Resources Fisheries Research Laboratory Staff Ms. Aida Rosario (Director and SEAMAP-C Committee Chairperson) Ms. Aida Rosario (Director and SEAMAP-C Committee Chairperson) Ms. Nilda Jimenez (SEAMAP-C Data Manager) Ms. Nilda Jimenez (SEAMAP-C Data Manager) Mr. Daniel Matos (Fishery-Dependent Data) Mr. Daniel Matos (Fishery-Dependent Data) Department of Marine Sciences, UPRM Department of Marine Sciences, UPRM Dr. Francisco Pagán Dr. Francisco Pagán Michael Nemeth Michael Nemeth Michelle Schärer Michelle Schärer Insight from Dr. Edgardo Ojeda (PR Seagrant) and Dr. David Mann (U South Florida) during their concurrent red hind aggregation studies Insight from Dr. Edgardo Ojeda (PR Seagrant) and Dr. David Mann (U South Florida) during their concurrent red hind aggregation studies


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