Statistical Analysis of Historic Recreational Fishing Catch Rates in Lake Worth Lagoon Using the Historic Fishing Records of the West Palm Beach Fishing Club Manuel McIlroy Florida Atlantic University
Outline 1. Introduction to WPBFC 2. Total Catch in LWL 3. Catches by Locations in LWL 4. Average Weight 5. Snook Statistics Most Caught Species 6. Spotted Sea Trout Indicator Species of Estuary Health 7. Conclusions
West Palm Beach Fishing Club Founded in 1934 Has closely cooperated with state and local leaders to enhance and protect coastal habitats, especially Lake Worth Lagoon (LWL) Have been recording member s catches from 1946 to present
Records Information One catch affidavit for each individual fish caught Information recorded for this analysis 1. Species of Fish 2. Month and Year of Catch 3. Location of Catch 4. Weight (pounds and ounces) if available 5. Length (inches) if available For this analysis I used record that pertained to a fish being caught in LWL from Jan. 195 to Dec. 29
Fish Caught (Individuals) Total Fish Catches in Lake Worth Lagoon Total Fish Caught vs. Decade 6 5 4 3 2 Grand total fish caught Linear (Grand total fish caught) 1 195 196 197 198 199 2
Species Counts (Individuals) Total Catches by Locations within Lake Worth Lagoon 35 Species Counts by Location 3 25 2 15 1 5 Lake Worth Lake Worth Inlet Munyon Island Palm Beach Inlet Peanut Island Singer Island 195 196 197 198 199 2
Fish Caught (Individuals) Average Weight (lbs) Average Fish Weight Randomly sampled 119 catch records for each decade Research suggests that overfishing larger fish may lead to a pop. of smaller, less fertile fish. 1 3 25 2 15 1 5 Average Weight (lbs) of Fish Caught 194 195 196 197 198 199 2 21 6 4 2 Total Fish Caught vs. Decade 195 196 197 198 199 2 Avg Weight (lbs) Linear (Avg Weight (lbs)) Grand total fish caught Linear (Grand total fish caught)
# Fish Caught Weight (lbs) Snook #1 Target Species of LWL 14 Total Snook Catches 35 Average Weight (lbs) 12 3 1 25 8 2 6 15 4 1 2 5 194 195 196 197 198 199 2 21 194 195 196 197 198 199 2 21
# Fish Caught % Catch Snook Catch and Abundance by Location Total Catches Relative Abundance 12 4 1 35 3 8 25 6 Lake Worth 2 Lake Worth 4 Palm Beach Inlet 15 Palm Beach Inlet 1 2 5 194 196 198 2 22 194 196 198 2 22
Spotted Sea Trout Commonly used an as estuarine indicator species Non-migratory species, so they spend their entire lives within 5-1 miles of home estuary Growth rates can serve as indicator of subtle changes in the biotic and abiotic conditions within an estuary 2 Mortality rates could also be used as an indication of estuarine health 3
# Fish Caught Weight (lbs) Spotted Sea Trout Indicator Species 7 Total Catches 16 Average Weight (lbs) 6 5 14 12 4 3 2 1 1 8 6 4 2 194 195 196 197 198 199 2 21 194 195 196 197 198 199 2 21
# Fish Caught % Catch Spotted Sea Trout Catch and Abundance by Location Total Catches Relative Abundance 7 25 6 2 5 4 15 3 Lake Worth Palm Beach Inlet 1 Lake Worth Palm Beach Inlet 2 1 5 194 196 198 2 22 194 196 198 2 22
% Catch % Catch Relative Abundances by Location 4 Lake Worth Relative Abundance Palm Beach Inlet Relative Abundance 35 35 3 3 25 25 2 15 1 Snook Jack Crevalle Spotted Sea Trout 2 15 1 Snook Jack Crevalle Spotted Sea Trout 5 5 194 196 198 2 22 194 196 198 2 22
Conclusions In general fish abundances and weights have been in decline since the 197s Possible causes include overfishing and habitat degradation Highlights the need for restoration and further fisheries research If fishing catch rates can be brought back to the 195s and 6s level through habitat restoration, it would be not just an ecological benefit, but an economic boom as well Solutions can come from integration of scientific research with expert knowledge and government support
Acknowledgements I d like to thank Tom Twyford and the entire West Palm Beach Fishing Club for allowing access to their historic records. I d also like to thank Paul Davis, Alyssa Dodd, and Eric Anderson of the Palm Beach County Environment Resources Management Division for providing important LWL environmental data.
References 1. van Wijk, et al. (213) Experimental harvesting of fish populations drives genetically based shifts in body size and maturation. Front Ecol Envirnon. Vol. 11 (4) pp. 181-187. 2. Bortone, et al. (26) Spotted seatrout (Family Sciaenidae) growth as an indicator of estuarine conditions in San Carlos Bay, Florida. Publications For Sale, 127. 3. Peebles, et al. (1988). Distribution, growth and mortality of larval spotted seatrout, Cynoscion nebulosus: a comparison between two adjacent estuarine areas of southwest Florida. Bulletin of marine science, 42(3), pp. 397-41
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