The potential of the Fiddler Crabs for secondary productivity of mangroves and the maintenance of fishery resources

• Grant number: 21/04124-2
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2021
• End date: August 31, 2025
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Ronaldo Adriano Christofoletti
• Grantee: Fernando Rafael de Grande
• Host Institution: Instituto do Mar (IMar). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated scholarship(s): 22/12556-2 - Impact of rising temperatures on global mangrove secondary production, BE.EP.PD

Abstract

Mangroves are known to be productive environments that play important ecological functions, such as, for example, nursery for marine life, protection of the coastline, carbon sink and the production of fishery resources. Although the productivity of mangroves is an ecosystem service of great value, studies on this subject are mainly focused on the investigation of primary production. However, most economically important fish species benefit from the secondary productivity of the mangroves, since they feed on lower-trophic levels consumer organisms. In Brazilian mangroves, the Fiddler Crabs have the potential to be one of the main contributors to secondary production, due to their high abundance and general distribution. Fiddler Crabs produce pelagic larvae that thrive in coastal marine environments adjacent to mangroves and, therefore, constitute a food resource for planktophagous fish. Although the contribution of Fiddler Crabs to secondary productivity is not yet well understood, it may be affected by climate changes, as these crustaceans are organisms sensitive to thermal variations. The aim of this study is to evaluate the potential of secondary productivity of Fiddler Crabs larvae in the Santos / São Vicente estuary and their use by fish of commercial importance. The presence of ovigerous females and the environmental temperature in populations of four species of Fiddler Crabs will be monitored. In the laboratory, larval production by species will be estimated and it will be tested whether the fertility of the females is affected by the increase in temperature. The density of the Fiddler Crabs larvae in coastal waters will be assessed according to the distance from the coast and the season. Finally, it will be evaluated which are the main economically important fish that feed on the Fiddler Crabs larvae.We intend with this study to elucidate the ecological and economic importance of mangroves and to assess the sensitivity to climate change of one of its most characteristic mangrove ecosystem services: the productivity. (AU)