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Gomes M, Lopes VM, Mai MG, Paula JR, Bispo R, Batista H, Barraca C, Baylina N, Rosa R, Pimentel MS. Impacts of acute hypoxia on the short-snouted seahorse metabolism and behaviour. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166893. [PMID: 37696409 DOI: 10.1016/j.scitotenv.2023.166893] [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: 06/27/2023] [Revised: 08/31/2023] [Accepted: 09/02/2023] [Indexed: 09/13/2023]
Abstract
Seahorses are one of the most unique and enigmatic animals, recognized as flagship species for several conservation issues. Unfortunately, seahorses' populations have been declining and their unique lifestyle may constrain the ability of these animals to evolve in the future climate scenarios. They inhabit shallow coastal waters that display daily or seasonal environmental fluctuations. Yet, few studies have scrutinized the impacts of climate changes on these iconic species. Within this context, the objective of this work was to test the effects of an extreme hypoxia exposure (~27 % dissolved oxygen for approximately 7 h) on the metabolism, behaviour and food intake of the temperate seahorse Hippocampus hippocampus. Regarding metabolism, hypoxia exposure led to a significant reduction in metabolic rates and an increase in ventilation rates. Seahorses showed signs of movement lethargy under oxygen depletion. The results show that a small but extreme exposure to hypoxia is tolerable by seahorses despite inducing metabolic and behavioural changes, that may jeopardize the future development and survival of these iconic organisms.
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Affiliation(s)
- Matilde Gomes
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
| | - Vanessa M Lopes
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - Monica G Mai
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - José R Paula
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
| | - Regina Bispo
- Center for Mathematics and Applications (NovaMath), FCT NOVA and Department of Mathematics, FCT NOVA, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Hugo Batista
- Oceanário de Lisboa, Esplanada D. Carlos I, 1900-005 Lisbon, Portugal
| | - Catarina Barraca
- Oceanário de Lisboa, Esplanada D. Carlos I, 1900-005 Lisbon, Portugal
| | - Núria Baylina
- Oceanário de Lisboa, Esplanada D. Carlos I, 1900-005 Lisbon, Portugal
| | - Rui Rosa
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
| | - Marta S Pimentel
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
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Borges AKM, Alves RRN, Oliveira TPR. Mapping seahorses in a Brazilian estuary: mangrove structures as key predictors for distribution and habitat preference. PeerJ 2023; 11:e15730. [PMID: 37489120 PMCID: PMC10363342 DOI: 10.7717/peerj.15730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 06/18/2023] [Indexed: 07/26/2023] Open
Abstract
Planning for effective conservation demands an accurate understanding of the ecological aspects of species, particularly their distribution and habitat preferences. This is even more critical in the case of data-poor, rare, and threatened species, such as seahorses, mainly when they inhabit vulnerable ecosystems like estuaries. Given the importance of better understanding these parameters to design seahorse conservation strategies, we mapped the distribution and assessed habitat preferences of longsnout seahorses (Hippocampus reidi) in a mangrove estuary in a Brazilian protected area. Using generalised linear mixed-effects models we found that dense mangrove cover macro-habitats and shallow depths predicted seahorse sightings and higher densities. Furthermore, the selective index of micro-habitats used by seahorses showed that seahorses exhibited a preference for mangrove structures as holdfasts (i.e., fallen branches). Due to the significant importance of mangroves in providing suitable habitats for H. reidi in estuaries, it is crucial to enforce the protection of these ecosystems in conservation and management strategies for the species.
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Affiliation(s)
- Anna Karolina Martins Borges
- Programa de Pós-Graduação em Etnobiologia e Conservação da Natureza, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil
- LAPEC—Laboratório de Peixes e Conservação Marinha, Universidade Estadual da Paraíba, João Pessoa, Paraíba, Brazil
| | - Rômulo Romeu Nóbrega Alves
- Programa de Pós-Graduação em Etnobiologia e Conservação da Natureza, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil
- Departamento de Biologia, Universidade Estadual da Paraíba, Campina Grande, Paraíba, Brazil
| | - Tacyana Pereira Ribeiro Oliveira
- Programa de Pós-Graduação em Etnobiologia e Conservação da Natureza, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil
- LAPEC—Laboratório de Peixes e Conservação Marinha, Universidade Estadual da Paraíba, João Pessoa, Paraíba, Brazil
- Centro de Ciências Biológicas e Sociais Aplicadas, Universidade Estadual da Paraíba, João Pessoa, Paraíba, Brasil
- International Union for Conservation of Nature (IUCN) Species Survival Commission, Seahorse, Pipefish and Seadragon Specialist Group, Gland, Switzerland
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Takaya K, Sasaki Y, Ise T. Automatic detection of alien plant species in action camera images using the chopped picture method and the potential of citizen science. BREEDING SCIENCE 2022; 72:96-106. [PMID: 36045894 PMCID: PMC8987844 DOI: 10.1270/jsbbs.21062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/20/2021] [Indexed: 06/15/2023]
Abstract
Monitoring and detection of invasive alien plant species are necessary for effective management and control measures. Although efforts have been made to detect alien trees using satellite images, the detection of alien herbaceous species has been difficult. In this study, we examined the possibility of detecting non-native plants using deep learning on images captured by two action cameras. We created a model for each camera using the chopped picture method. The models were able to detect the alien plant Solidago altissima (tall goldenrod) and obtained an average accuracy of 89%. This study proved that it is possible to automatically detect exotic plants using inexpensive action cameras through deep learning. This advancement suggests that, in the future, citizen science may be useful for conducting distribution surveys of alien plants in a wide area at a low cost.
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Affiliation(s)
- Kosuke Takaya
- Graduate School of Agriculture, Kyoto University, Kitashirakawaoiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yu Sasaki
- Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kitashirakawaoiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takeshi Ise
- Field Science Education and Research Center, Kyoto University, Kitashirakawaoiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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Unger S, Bodinof Jachowski CM, Diaz L, Williams LA. Shelter Guarding Behavior of the Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) in North Carolina Streams. SOUTHEAST NAT 2020. [DOI: 10.1656/058.019.0411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Shem Unger
- Department of Biology, Wingate University, Wingate, NC 28174
| | | | - Lauren Diaz
- Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634
| | - Lori A. Williams
- North Carolina Wildlife Resources Commission, 1722 Mail Service Center, Raleigh, NC 27699
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Claassens L, Harasti D. Life history and population dynamics of an endangered seahorse (Hippocampus capensis) within an artificial habitat. JOURNAL OF FISH BIOLOGY 2020; 97:974-986. [PMID: 32621517 DOI: 10.1111/jfb.14452] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/18/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Species-specific life-history information is critical for successful conservation, particularly in establishing an accurate baseline status. Obtaining such information is challenging for most species, but in particular for rare and threatened marine species. To facilitate future conservation of the endangered Knysna seahorse (Hippocampus capensis) this study aimed to determine important life-history information for this species. Visible implant fluorescent elastomer (VIFE) tags were used to mark 78 seahorses within a residential marina estate in the Knysna estuary, South Africa, in February 2018. Using a mark-resight approach, the size and movement patterns of the population and growth rate of seahorses were determined over a 14-month period. The closed population estimate for H. capensis, within Thesen Islands Marina, was estimated to be 134 (118-152 95% C.I.) in February 2018 compared to only 72 (48-108 95% C.I.) in February 2019. The species showed rapid initial growth with males and females having similar rates of growth based on the specialised von Bertalanffy growth function model. The importance of Reno mattresses as a habitat for H. capensis was confirmed based on the high abundance and site fidelity of the population, which emphasises the conservation potential of heavily modified environments for threatened seahorse species. The use of VIFE tags was deemed effective in studying this endangered seahorse and allowed the collection of important information for this species which can be used in future Red List assessments and conservation actions.
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Affiliation(s)
- Louw Claassens
- Department of Zoology & Entomology, Rhodes University, Grahamstown, Republic of South Africa
- Knysna Basin Project, Knysna, Republic of South Africa
| | - David Harasti
- Fisheries Research, NSW Department of Primary Industries, Taylors Beach, New South Wales, Australia
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Arendse CJ, Russell IA. Morphometric regressions for the endangered Knysna seahorse, Hippocampus capensis, in the Swartvlei Estuary from mass stranding events. KOEDOE: AFRICAN PROTECTED AREA CONSERVATION AND SCIENCE 2020. [DOI: 10.4102/koedoe.v62i1.1632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
No abstract available.
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Claassens L, Hodgson AN. Monthly population density and structure patterns of an endangered seahorse Hippocampus capensis: a comparison between natural and artificial habitats. JOURNAL OF FISH BIOLOGY 2018; 92:2000-2015. [PMID: 29675915 DOI: 10.1111/jfb.13639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 04/08/2018] [Indexed: 06/08/2023]
Abstract
This study investigated aspects of the population ecology of the endangered Knysna seahorse Hippocampus capensis within different habitat types. High densities of H. capensis were found within artificial Reno mattress habitat, within the Knysna Estuary, South Africa. Monthly surveys at three sites were conducted from October 2015 to August 2016 to compare population densities of H. capensis in this artificial habitat with natural eel grass Zostera capensis habitat. Hippocampus capensis densities varied significantly across all sites and highest population densities were consistently observed within the Reno mattress habitat. Hippocampus capensis were also found to be significantly larger within the Reno mattress habitat and pooled data showed that males were significantly larger than females. The overall sex ratio for all three sites was female biased, although this varied across seasons at two sites. The findings suggest that artificial Reno mattresses provide novel habitat for this endangered species and consideration should be given to the usefulness of these structures in future conservation actions.
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Affiliation(s)
- L Claassens
- Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa
- Knysna Basin Project, Knysna, 6570, South Africa
| | - A N Hodgson
- Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa
- Knysna Basin Project, Knysna, 6570, South Africa
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