Large-scale, multidirectional larval connectivity amongcoral reef fish populations in the Great Barrier ReefMarine Park

• Published in: Molecular ecology 2016-12
• Main Authors: Williamson, David H., Harrison, Hugo B., Almany, Glenn R., Berumen, Michael L., Bode, Michael, Bonin, Mary C., Choukroun, Severine, Doherty, Peter J., Frisch, Ashley John, Saenz-Agudelo, Pablo, Jones, Geoffrey P.
• Format: Article
• Language: English
• Subjects: Biodiversity and Ecology; Environmental Sciences; Life Sciences; Reproductive Biology
• ISSN: 0962-1083; 1365-294X
• DOI: 10.1111/mec.13908

Larval dispersal is the key process by which populations of most marine fishes andinvertebrates are connected and replenished. Advances in larval tagging and geneticshave enhanced our capacity to track larval dispersal, assess scales of population con-nectivity, and quantify larval exchange among no-take marine reserves and fishedareas. Recent studies have found that reserves can be a significant source of recruitsfor populations up to 40 km away, but the scale and direction of larval connectivityacross larger seascapes remain unknown. Here, we apply genetic parentage analysis toinvestigate larval dispersal patterns for two exploited coral reef groupers (Plectropomusmaculatus and Plectropomus leopardus) within and among three clusters of reefs sepa-rated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of thetotal juveniles sampled, respectively) were genetically assigned to parent individualson reefs within the study area. We identified both short-distance larval dispersalwithin regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to~250 km among regions. Dispersal strength declined significantly with distance, withbest-fit dispersal kernels estimating median dispersal distances of ~110 km for P. mac-ulatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates thatestablished reserves form a highly connected network and contribute larvae for thereplenishment of fished reefs at multiple spatial scales. Our findings highlight thepotential for long-distance dispersal in an important group of reef fishes, and providefurther evidence that effectively protected reserves can yield recruitment and sustain-ability benefits for exploited fish populations.