Complex larval connectivity patterns among marine invertebrate populations

Abstract

Based on the belief that marine larvae, which can spend days to months in the planktonic stage, could be transported considerable distances by ocean currents, it has long been assumed that populations of coastal species with a planktonic larval stage are demographically open and highly ''connected.'' Such assumptions about the connectivity of coastal populations govern approaches to managing marine resources and shape our fundamental understanding of population dynamics and evolution, yet are rarely tested directly due to the small size and high mortality of marine larvae in a physically complex environment. Here, we document a successful application of elemental fingerprinting as a tracking tool to determine sources of settled invertebrates and show that coastal mussel larvae, previously thought to be highly dispersed, can be retained within 20 -30 km of their natal origin. We compare two closely related and co-occurring species, Mytilus californianus and Mytilus galloprovincialis, and determine that, despite expected similarities, they exhibit substantially different connectivity patterns. Our use of an in situ larval culturing technique overcomes the previous challenge of applying microchemical tracking methods to species with completely planktonic development. The exchange of larvae and resulting connectivities among marine populations have fundamental consequences for the evolution and ecology of species and for the management of coastal resources.elemental fingerprinting ͉ in situ larval culturing ͉ larval retention ͉ larval transport ͉ Mytilus

Local retention, dispersal and fluctuating connectivity among populations of a coral reef fish

“…Therefore, populations within the boundaries of a marine reserve can, perhaps, provide recruitment subsidies to areas as distant as *200 km or greater from the reserve. Generally, the spatial scale of demographic connectivity in this system appears to match predictions from hydrodynamic models (Cowen et al 2006) and recent empirical data (Becker et al 2007;Planes et al 2009) which suggest that populations are likely to receive significant larval inputs primarily from sources spaced less than 100 km away. The observed dispersal directions also appear to match model predictions.…”

“…This metric is much harder to estimate as it requires information about larval exchange among a network of populations. Few studies have tracked larval dispersal among populations (Miller and Shanks 2004;Becker et al 2007;Planes et al 2009;Shima and Swearer 2009); fewer still have empirically estimated temporal variation in dispersal (Miller and Shanks 2004); and none have empirically investigated the degree of temporal stability in connectivity among a network of populations.…”

Reestablecimiento de Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae) en el norte de Chile

“…Distribuciones importantes de larvas del pectínido Pecten maximus (Linnaeus), en tamaño y densidad en áreas desprovistas de progenitores, han sido explicadas para el Canal de la Mancha, por un transporte horizontal que generan las mareas y vientos, desde otros sitios de desove (Boucher & Dao, 1990). Además, diversos autores (Caley et al, 1996;Warner, 1997;Neubert & Caswell, 2000;Strathmann et al, 2002;Palumbi, 2004;Harley et al, 2006;Becker et al, 2007), consideran que el conocimiento cuantitativo de conectividades larvales ha revolucionado la comprensión de una amplia gama de asuntos, incluyendo la dinámica de poblaciones marinas, los procesos de extinción local y de nuevas colonizaciones, las escalas de adaptación, el diseño de reservas marinas, la propagación de especie invasoras y la respuesta de las especies al cambio climático.…”

The influence of oceanographic fronts and early-life-history traits on connectivity among littoral fish species

“…Significant progress has recently been made in our ability to accurately track pelagic stages (20)(21)(22), as well as in determining genetic connectivity patterns by combining oceanographic models and molecular genetic data (23)(24)(25). However, relatively few empirical studies have investigated how oceanographic conditions influence larval dispersal and ultimately gene flow among marine fishes with varying life-history strategies (7,26,27).…”