Local Replenishment of Coral Reef Fish Populations in a Marine Reserve

Australian Research Council Centre of Excellence for Coral Reef Studies and School of Marine and Tropical Biology, James Cook University, Townsville QLD 4811, Australia.
Science (Impact Factor: 33.61). 06/2007; 316(5825):742-4. DOI: 10.1126/science.1140597
Source: PubMed


The scale of larval dispersal of marine organisms is important for the design of networks of marine protected areas. We examined
the fate of coral reef fish larvae produced at a small island reserve, using a mass-marking method based on maternal transmission
of stable isotopes to offspring. Approximately 60% of settled juveniles were spawned at the island, for species with both
short (<2 weeks) and long (>1 month) pelagic larval durations. If natal homing of larvae is a common life-history strategy,
the appropriate spatial scales for the management and conservation of coral reefs are likely to be much smaller than previously

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    • "Empirical studies of self-recruitment and connectivity are limited in number and often restricted to single dispersal events (Jones et al. 1999; Almany et al. 2007; D&apos;Aloia et al. 2013; Schunter et al. 2014). However, investigating the temporal variability of dispersal patterns at several seasonal and interannual scales is essential for understanding the degree of openness of marine populations , thus inferring sizing and spacing of marine protected area networks (e.g., Pusack et al. 2014). "
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    ABSTRACT: Understanding the dynamics of marine populations is critical to managing marine systems effectively and requires information on patterns of population dispersal and connectivity that are still poorly known. We used transgenerational marking to study larval dispersal of the humbug damselfish, Dascyllus aruanus, in the patchy reef seascape of the southwest Lagoon of New Caledonia (SWL), southwest tropical pacific. The adult population of a patch reef located in the central part of the SWL was injected repeatedly with an enriched 137Ba solution to ensure mass production of marked larvae over two successive reproductive seasons. Multiple cohorts of newly settled larvae were sampled, and their otolith core was analyzed by laser ablation inductively coupled plasma mass spectrometry to assess the seasonal and interannual variability of self-recruitment at the central reef. Connectivity between this reef and ten neighboring reefs was also estimated. Analysis of >1200 settlers indicated that self-recruitment varied significantly between months (ranging from 0 to 68 %) and years (21 % in 2011 and 0 % in 2012). However, variable self-recruitment did not always correspond to variable numbers of self-recruits. Therefore, whereas self-recruitment is undoubtedly a good indication of the degree of population openness, it may not indicate local population persistence. Finally, being the first self-recruitment study to include such a large number of settlers, our study reveals that the threshold used to determine marked individuals significantly affects perceived self-recruitment and connectivity rates and, therefore, must be carefully chosen.
    Coral Reefs 09/2015; 34(3). DOI:10.1007/s00338-015-1300-4 · 3.32 Impact Factor
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    • "Our focal species is regularly used to model coral reef fish connectivity in the Coral Triangle (Almany et al. 2007; Berumen et al. 2012b; Pratchett et al. 2014). Evidence of reef fish population connectivity is an important driver for improved reef management and the implementation of notake marine reserves (Almany et al. 2007; Jones et al. 2009; Berumen et al. 2012b), but reef-scale variability in key life history traits for this species is not yet known. "
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    ABSTRACT: Recent research has demonstrated that, despite a pelagic larval stage, many coral reef fishes disperse over relatively small distances, leading to well-connected populations on scales of 0–30 km. Although variation in key biological characteristics has been explored on the scale of 100–1000 s of km, it has rarely been explored at the scale relevant to actual larval dispersal and population connectivity on ecological timescales. In this study, we surveyed the habitat and collected specimens (n = 447) of juvenile butterflyfish, Chaetodon vagabundus, at nine sites along an 80-km stretch of coastline in the central Philippines to identify variation in key life history parameters at a spatial scale relevant to population connectivity. Mean pelagic larval duration (PLD) was 24.03 d (SE = 0.16 d), and settlement size was estimated to be 20.54 mm total length (TL; SE = 0.61 mm). Both traits were spatially consistent, although this PLD is considerably shorter than that reported elsewhere. In contrast, post-settlement daily growth rates, calculated from otolith increment widths from 1 to 50 d post-settlement, varied strongly across the study region. Elevated growth rates were associated with rocky habitats that this species is known to recruit to, but were strongly negatively correlated with macroalgal cover and exhibited negative density dependence with conspecific juveniles. Larger animals had lower early (first 50 d post-settlement) growth rates than smaller animals, even after accounting for seasonal variation in growth rates. Both VBGF and Gompertz models provided good fits to post-settlement size-at-age data (n = 447 fish), but the VBGF’s estimate of asymptotic length (L∞ = 168 mm) was more consistent with field observations of maximum fish length. Our findings indicate that larval characteristics are consistent at the spatial scale at which populations are likely well connected, but that site-level biological differences develop post-settlement, most likely as a result of key differences in quality of recruitment habitat.
    Coral Reefs 07/2015; 34(4). DOI:10.1007/s00338-015-1330-y · 3.32 Impact Factor
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    • "Originally thought to have scales of 100–1000 km, Cowen et al. (2000, 2006) who modeled meso-scale oceanography and assumed larvae are passive particles concluded the scale of self-recruiting populations should be considered to be 10–100 km. While experimental studies in the field are now concluding self-recruiting populations of Indo-Pacific reef fish species can occur at scales of 1–10 km (Jones et al., 1999, 2005; Almanny et al., 2007; Planes et al., 2009). "
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    ABSTRACT: The theoretical basis of a new approach to data poor fisheries assessment, length-based assessment of spawning potential ratio, has been recently published. This paper describes its first application over two years to assess 12 of the 15 most numerous species of Indo-Pacific coral reef fish in Palau. This study demonstrates the techniques applicability to small-scale data-poor fisheries and illustrates the type of data required, and the assessment's outputs. A methodology is developed for extending the principles of Beverton–Holt Life History Invariants to use the literature on related species within the Indo-Pacific reef fish assemblage to 'borrow' the information needed to parameterize assessments for Palau's poorly studied stocks. While the assessments will continue to be improved through the collection of more size and maturity data, and through further synthesis of the literature, a consistent and coherent picture emerges of a heavily fished assemblage with most assessed species having SPR < 20% and many <10%. Beyond the technical aspects of this study, the relative simplicity of the data being collected and the underlying concept of spawning potential facilitated the involvement of fishers in collecting their own data and community ownership of the results.
    Fisheries Research 07/2015; 171:42-58. DOI:10.1016/j.fishres.2015.06.008 · 1.90 Impact Factor
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