The great variability and transience of regional plankton likely drive their foraging behavior, prey sources, and habitat use ( Stewart et al., 2017 Barr and Abelson, 2019 Putra et al., 2020). Being large filter feeders, manta rays spend their lives in proximity to where plankton blooms occur, these being elicited by temporal and spatial environmental cues ( Sims et al., 2005 Armstrong et al., 2021). Manta rays (Family Mobulidae) are pelagic planktivores that aggregate in regions supporting high zooplankton densities and cleaning stations, where symbiotic fish remove parasites from them ( Feder, 1966 Couturier et al., 2012 Stevens, 2016 White et al., 2017). Our study provides valuable baseline data for future research and underscores the need for continued monitoring and protection of these iconic marine species. The significant decline and spatial-temporal patterns we observed have critical implications for management and conservation efforts. These findings highlight the importance of South African waters as a seasonal habitat for manta rays along the southern African coastline. We further found that a greater proportion (70%) of juveniles were caught in the southernmost sampled area, from Hibberdene in the north to Mzamba in the south. Over half of the caught individuals were juveniles, and a total of 841 individuals (52% of the total catch) belonged to the confirmed juvenile size class (1400-2500 mm disc width). We also observed that moon phase had an effect on manta ray presence, with significantly more catches during spring tides at new and full moon phases. We found that manta rays were caught at least once in all 46 netted beaches along the 350 km span of coastline, but with significantly more catches in the Central Area, between Anstey’s beach in the north and Mtwalume in the south. Our analysis revealed a significant decline in overall manta ray catches since the late 1990s (p<0.0001), with increased catch rates during summer, suggesting seasonal visitation to South African waters. We also evaluated the size composition and demographics of caught manta rays using the same dataset. We used Generalized Additive Models and the probability of encounter to assess annual and seasonal trends, as well as the effect of location and moon phases on catch rates. This study analyzed a 41-year dataset from the KwaZulu-Natal bather protection program to investigate catch per unit effort between 1981-2021. birostris) are poorly understood in South Africa, despite their ecological importance and charismatic appeal. 4School of Biological and Marine Sciences, University of Plymouth, Plymouth, United Kingdom.3Department of Marine Biology, KwaZulu-Natal Sharks Board, Umhlanga, Durban, South Africa.2Department of Forestry, Fisheries and the Environment (DFFE), Cape Town, South Africa.1Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town, South Africa.Michelle Carpenter 1*, Denham Parker 1,2, Matthew L.
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