1
|
Oduor NA, Munga CN, Imbayi LK, Botwe PK, Nyanjong EO, Muthama CM, Mise NA, Moosdorf N. Anthropogenic nutrients and phytoplankton diversity in Kenya's coastal waters: An ecological quality assessment of sea turtle foraging sites. MARINE POLLUTION BULLETIN 2024; 199:115897. [PMID: 38128251 DOI: 10.1016/j.marpolbul.2023.115897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/14/2023] [Accepted: 12/02/2023] [Indexed: 12/23/2023]
Abstract
We assessed ecological quality status (EQS) of coastal waters following claims of increasing sea turtle fibro-papillomatosis (FP) infections in Kenya, a disease hypothesized to be associated with 'poor' ecological health. We established widespread phosphate (P) and silicate (Si) limitation, dissolved ammonium contamination and an increase in potential harmful algal blooming species. Variations in the EQS was established in the sites depending on the indicators used and seasons. Generally, more sites located near hotels, tidal creeks, and estuarine areas showed 'poor', and 'bad' EQS during rainy period compared to dry season. Additionally, 90.1 % of the sites in 'poor' and 'bad' EQS based on dissolved inorganic nitrogen. Low dissolved oxygen, elevated temperature, salinity and ammonium, 'poor' EQS based on DIN, and potential bio-toxin-producing phytoplankton species characterized the FP prevalent areas, specifically during the dry season suggesting environmental stress pointing to the hypothesized connection between ecological and sea turtle health.
Collapse
Affiliation(s)
- Nancy A Oduor
- Leibniz Centre for Tropical Marine Research (ZMT), Fahrenheitstrasse 6, 28359 Bremen, Germany; Eracoma Ltd, P.O. Box 48664, Nairobi, Kenya; Faculty of Mathematics and Natural Sciences, Kiel University (CAU), Germany.
| | - Cosmas N Munga
- Department of Environment and Health Sciences, Marine and Fisheries Programme, Technical University of Mombasa (TUM), P.O. Box 90420, 80100 Mombasa, Kenya
| | - Linet K Imbayi
- Department of Oceanography and Hydrography, Kenya Marine and Fisheries Research Institute (KMFRI), P.O. Box 81651, 80100 Mombasa, Kenya
| | - Paul K Botwe
- Leibniz Centre for Tropical Marine Research (ZMT), Fahrenheitstrasse 6, 28359 Bremen, Germany; Department of Biological, Environmental, and Occupational Health Sciences, School of Public Health, University of Ghana, P.O. Box L.G. 13, Accra, Ghana
| | - Ezekiel O Nyanjong
- Department of Oceanography and Hydrography, Kenya Marine and Fisheries Research Institute (KMFRI), P.O. Box 81651, 80100 Mombasa, Kenya
| | - Charles M Muthama
- Department of Oceanography and Hydrography, Kenya Marine and Fisheries Research Institute (KMFRI), P.O. Box 81651, 80100 Mombasa, Kenya
| | | | - Nils Moosdorf
- Leibniz Centre for Tropical Marine Research (ZMT), Fahrenheitstrasse 6, 28359 Bremen, Germany; Faculty of Mathematics and Natural Sciences, Kiel University (CAU), Germany
| |
Collapse
|
2
|
Christiaanse JC, Antolínez JAA, Luijendijk AP, Athanasiou P, Duarte CM, Aarninkhof S. Distribution of global sea turtle nesting explained from regional-scale coastal characteristics. Sci Rep 2024; 14:752. [PMID: 38191897 PMCID: PMC10774326 DOI: 10.1038/s41598-023-50239-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 12/17/2023] [Indexed: 01/10/2024] Open
Abstract
Climate change and human activity threaten sea turtle nesting beaches through increased flooding and erosion. Understanding the environmental characteristics that enable nesting can aid to preserve and expand these habitats. While numerous local studies exist, a comprehensive global analysis of environmental influences on the distribution of sea turtle nesting habitats remains largely unexplored. Here, we relate the distribution of global sea turtle nesting to 22 coastal indicators, spanning hydrodynamic, atmospheric, geophysical, habitat, and human processes. Using state-of-the-art global datasets and a novel 50-km-resolution hexagonal coastline grid (Coastgons), we employ machine learning to identify spatially homogeneous patterns in the indicators and correlate these to the occurrence of nesting grounds. Our findings suggest sea surface temperature, tidal range, extreme surges, and proximity to coral and seagrass habitats significantly influence global nesting distribution. Low tidal ranges and low extreme surges appear to be particularly favorable for individual species, likely due to reduced nest flooding. Other indicators, previously reported as influential (e.g., precipitation and wind speed), were not as important in our global-scale analysis. Finally, we identify new, potentially suitable nesting regions for each species. On average, [Formula: see text] of global coastal regions between [Formula: see text] and [Formula: see text] latitude could be suitable for nesting, while only [Formula: see text] is currently used by turtles, showing that the realized niche is significantly smaller than the fundamental niche, and that there is potential for sea turtles to expand their nesting habitat. Our results help identify suitable nesting conditions, quantify potential hazards to global nesting habitats, and lay a foundation for nature-based solutions to preserve and potentially expand these habitats.
Collapse
Affiliation(s)
- Jakob C Christiaanse
- Department of Hydraulic Engineering, Delft University of Technology, Delft, Netherlands.
| | - José A A Antolínez
- Department of Hydraulic Engineering, Delft University of Technology, Delft, Netherlands
| | - Arjen P Luijendijk
- Department of Hydraulic Engineering, Delft University of Technology, Delft, Netherlands
- Deltares , Delft, Netherlands
| | | | - Carlos M Duarte
- Biological Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Stefan Aarninkhof
- Department of Hydraulic Engineering, Delft University of Technology, Delft, Netherlands
| |
Collapse
|
3
|
Inteca G, Hagy B, Silva I, Amoda C, Cululo A, Farooq H. The tourism industry keeps beaches clean in Mozambique. MARINE POLLUTION BULLETIN 2023; 196:115615. [PMID: 37804669 DOI: 10.1016/j.marpolbul.2023.115615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 10/09/2023]
Abstract
In this study, we conducted the first assessment of the litter abundance, diversity and predictors in Mozambique, by collecting approximately 2 tons of litter along six beaches across the country. We tested whether population, touristic industry, fishing, and recreation activities predict the quantity of macro litter for each of the 11 types and 141 subtypes of litter. Overall, we found that plastics made up 60.1 % of the items across all sampled beaches. Following plastics, clothing objects accounted for the second most weight (20.4 %) while foam objects were the second most abundant (15.7 %). More importantly, our results show that the tourism industry is a strong predictor for lower levels of litter across most types of litter while population density and fishing activity were strong predictors for higher levels. Our findings suggest that the tourism industry plays a crucial role in the country by maintaining the beaches clean.
Collapse
Affiliation(s)
- Gélica Inteca
- Faculty of Natural Sciences, Lúrio University, P.O. Box 958, Pemba, Mozambique.
| | - Badru Hagy
- Oceanographic Institute of Mozambique, P.O. Box 4603, Maputo, Mozambique
| | - Isabel Silva
- Faculty of Natural Sciences, Lúrio University, P.O. Box 958, Pemba, Mozambique
| | - Carlota Amoda
- Oceanographic Institute of Mozambique, P.O. Box 4603, Maputo, Mozambique
| | - Aniceto Cululo
- Faculty of Natural Sciences, Lúrio University, P.O. Box 958, Pemba, Mozambique
| | - Harith Farooq
- Faculty of Natural Sciences, Lúrio University, P.O. Box 958, Pemba, Mozambique; Center for Macroecology, Evolution and Climate, Globe Institute, University of Copenhagen, P.O. Box 2100, Copenhagen, Denmark; Gothenburg Global Biodiversity Centre, University of Gothenburg, Gothenburg, P.O. Box 461, 405 30 Gothenburg, Sweden
| |
Collapse
|
4
|
Pritchard AM, Sanchez CL, Bunbury N, Burt AJ, Currie JC, Doak N, Fleischer-Dogley F, Metcalfe K, Mortimer JA, Richards H, van de Crommenacker J, Godley BJ. Green turtle population recovery at Aldabra Atoll continues after 50 yr of protection. ENDANGER SPECIES RES 2022. [DOI: 10.3354/esr01174] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Green turtles Chelonia mydas have been subject to high levels of anthropogenic exploitation, with harvesting at their nesting sites especially pronounced throughout the late 19th and early 20th centuries, leading to worldwide declines. Due to their delayed sexual maturity, long-term protection and monitoring is crucial to allow and accurately demonstrate population recovery. Subsequent to their exploitation, Aldabra Atoll (Republic of Seychelles) has offered the longest continuous protection for nesting green turtles anywhere in the Western Indian Ocean, beginning in 1968. Here, we document the continuing recovery of that population by estimating clutch production within 12 mo nesting seasons over 50 yr of monitoring. An estimated mean of 15297 clutches were laid annually between December 2014 and November 2019. This represents an increase of 173% since Aldabra’s intensive monitoring programme was initiated in 1980, and 410-�665% since 1968. Clutch number increases were recorded at all but 1 of 6 monitored beach groups around the atoll but were most pronounced at Settlement Beach, where exploitation of nesting females was historically most intense. Seasonality data since 2000 showed a year-round nesting season, with elevated activity in April-June peaking on average in May, and a potential shift to later in the year over time. This study highlights the considerable contribution of Aldabra Atoll to regional green turtle numbers and the benefit of long-term protection and monitoring at what can be considered a global reference site for this species.
Collapse
Affiliation(s)
- AM Pritchard
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall TR10 9FE, UK
| | - CL Sanchez
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
- Department of Biology, University of Pisa, Via A. Volta 6, 56126 Pisa, Italy
| | - N Bunbury
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall TR10 9FE, UK
| | - AJ Burt
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
- Department of Plant Sciences, Oxford University, South Parks Road, OX1 3RB, UK
| | - JC Currie
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
- South African National Biodiversity Institute, Kirstenbosch Botanical Gardens, Claremont, Cape Town, Western Cape 7735, South Africa
- Institute for Coastal and Marine Research, Nelson Mandela University, Gqeberha, 6031, South Africa
| | - N Doak
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
| | - F Fleischer-Dogley
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
| | - K Metcalfe
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall TR10 9FE, UK
| | - JA Mortimer
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
- Department of Biology, University of Florida, Gainesville, Florida 32611, USA
| | - H Richards
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
| | - J van de Crommenacker
- Seychelles Islands Foundation, La Ciotat Building, Mont Fleuri, Victoria, PO Box 853, Seychelles
| | - BJ Godley
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall TR10 9FE, UK
| |
Collapse
|