Marine traffic has increased unprecedentedly in recent decades presenting the most common and chronic source of ocean noise pollution. Fishes are of major biological, ecological and societal value with hearing range overlapping with boat noise frequencies. Yet, the impact of man-made noise on fish is poorly known. Recent studies point to detrimental effects but the assessment on direct individual fitness (using field-based experiments) and resulting changes at the population level are needed. Such studies are essential to contribute to mitigation and management measures. The present proposal will evaluate the effect of boat noise on reproductive success and early-life development and survival in two fishes that depend on vocal communication for reproduction but otherwise diverge in reproductive strategies. The (valuable) meagre (Argyrossomus regius) is a demersal broadcast spawner with pelagic larvae while the Lusitanian toadfish (Halobatrachus didactylus) breeds in nests where larval development takes place. This project will study (1) the influence of boat noise on meagre and toadfish calling behaviour, using real boat passages and playback experiments, in a military base (BA6, Tagus estuary) with restricted access to the public. Acoustic activity will be monitored from land or with a developed autonomous acoustic recorder (EPO patent) in the inner estuary. Acoustic telemetry will further assess meagre movements in relation to boat passes. (2) Boat noise playback experiments will study impacts on reproductive success in toadfish, as well as development and survival of eggs, larvae and juveniles in both species. All experiments except the one with meagre egg/larvae (due to their small size) will be field-based. Both field and lab playback experiments will be validated by comparing played-back sound pressure and particle motion with real boat passes using calibrated sensors. (3) Physiological stress responses at the endocrine and cellular level will be assessed by quantifying cortisol and oxidative stress / energy metabolism related biomarkers in the different life stages. This proposal is highly innovative as it will measure direct fitness traits in the field and will take into account both bottom-up (at cellular and physiological level) and top-down responses (modulated by species specific behavioural traits). We expect to see detrimental effects of noise on calling behaviour and reproduction due to masking and heightened stress responses. We further expect that meagre will avoid passing boats in contrast with toadfish that presents nest-site fidelity. The proposal concepts and outputs with be widely disseminated. This proposal will involve the synergy between 4 research centres with complementary skills (ISPA/ FCiências.ID: acoustics, larval development; Uevora: telemetry; Polytechnic of Leiria: biomarkers) and international collaborators, including 2 firms. Collaboration with NGOs will contribute to provide guidelines to regulators.
Boat noise; Breeding success; Development and survival; Fish
ISPA (Coord.); CRL (Coord.); FCiências.ID; University of Évora
MARE-Polytechnic of Leiria: Sara Calçada Novais – firstname.lastname@example.org
30.735,00 € (Polytechnic of Leiria)| POCI – Programa Operacional Competitividade e Internacionalização/FCT – Fundação para a Ciência e a Tecnologia // Duration 2018-2021