title: Mangrove habitat use by juvenile reef fish: meta-analysis reveals that tidal regime matters more than biogeographic region.
abstract: Identification of critical life-stage habitats is key to successful conservation efforts. Juveniles of some species show great flexibility in habitat use while other species rely heavily on a restricted number of juvenile habitats for protection and food. Considering the rapid degradation of coastal marine habitats worldwide, it is important to evaluate which species are more susceptible to loss of juvenile nursery habitats and how this differs across large biogeographic regions. Here we used a meta-analysis approach to investigate habitat use by juvenile reef fish species in tropical coastal ecosystems across the globe. Densities of juvenile fish species were compared among mangrove, seagrass and coral reef habitats. In the Caribbean, the majority of species showed significantly higher juvenile densities in mangroves as compared to seagrass beds and coral reefs, while for the Indo-Pacific region seagrass beds harbored the highest overall densities. Further analysis indicated that differences in tidal amplitude, irrespective of biogeographic region, appeared to be the major driver for this phenomenon. In addition, juvenile reef fish use of mangroves increased with increasing water salinity. In the Caribbean, species of specific families (e.g. Lutjanidae, Haemulidae) showed a higher reliance on mangroves or seagrass beds as juvenile habitats than other species, whereas in the Indo-Pacific family-specific trends of juvenile habitat utilization were less apparent. The findings of this study highlight the importance of incorporating region-specific tidal inundation regimes into marine spatial conservation planning and ecosystem based management. Furthermore, the significant role of water salinity and tidal access as drivers of mangrove fish habitat use implies that changes in seawater level and rainfall due to climate change may have important effects on how juvenile reef fish use nearshore seascapes in the future.
authors.affiliation: Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Animal Ecology and Ecophysiology, Nijmegen, The Netherlands; Tanzania Fisheries Research Institute, Dar es Salaam, Tanzania.
authors.forename: Mathias M
authors.initials: MM
authors.lastname: Igulu
authors.affiliation: Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Animal Ecology and Ecophysiology, Nijmegen, The Netherlands; Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, The University of Adelaide, Adelaide, Australia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Nagelkerken
authors.affiliation: Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Animal Ecology and Ecophysiology, Nijmegen, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Dorenbosch
authors.affiliation: Radboud University Nijmegen, Institute for Water and Wetland Research, Department of Animal Ecology and Ecophysiology, Nijmegen, The Netherlands.
authors.forename: Monique G G
authors.initials: MG
authors.lastname: Grol
authors.affiliation: Marine Spatial Ecology Laboratory and Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, Brisbane, Australia.
authors.forename: Alastair R
authors.initials: AR
authors.lastname: Harborne
authors.affiliation: Tanzania Fisheries Research Institute-Kigoma Center, Kigoma, Tanzania.
authors.forename: Ismael A
authors.initials: IA
authors.lastname: Kimirei
authors.affiliation: Marine Spatial Ecology Laboratory and Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, Brisbane, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Mumby
authors.affiliation: Australian Rivers Institute - Coast and Estuaries and School of Environment, Griffith University, Gold Coast, Australia.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Olds
authors.affiliation: College of Natural and Applied Sciences, Department of Aquatic Science and Fisheries, University of Dar es Salaam, Dar es Salaam, Tanzania.
authors.forename: Yunus D
authors.initials: YD
authors.lastname: Mgaya
mesh_terms: D000818:Animals; D057894:Coral Reefs; D005398:Fisheries; D005399:Fishes; D005843:Geography; D014197:Trees