Maturation and age in queen conch (Strombus gigas): Urgent need for changes in harvest criteria

Stoner, Allan W.; Mueller, Karl W.; Brown‐Peterson, Nancy J.; Davis, Martha H.; Booker, Catherine

doi:10.1016/j.fishres.2012.07.017

Cited by 45 publications

(72 citation statements)

References 29 publications

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“…For queen conch the density thresholds recommended by scientists and policy makers to support breeding is between 50 and 100 adult conch ha −1 (Stoner et al 2012a). Our ES survey expanded on both sides of the original RS survey within the ECLSP and included additional habitat that harbored high densities of breeding adults.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Efficacy of an established marine protected area at sustaining a queen conch Lobatus gigas population during three decades of monitoring

Kough¹,

Cronin²,

Skubel³

et al. 2017

Mar. Ecol. Prog. Ser.

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Marine Protected Areas (MPAs) are designed to conserve and preserve the ecosystems and cultural resources of the ocean. In theory, protected populations flourish, replenish adjacent regions, and are self-sustaining. However, describing the efficacy of MPAs requires long-term monitoring. Queen conch Lobatus gigas are iconic Caribbean denizens with populations that have been decimated by overfishing and are slow to rebound due to density-dependent breeding. The Exuma Cays Land and Sea Park (ECLSP) is a well-enforced, no-take, old, and large MPA. Surveys in 1994, 2011, and 2016 were used to track changes in the abundance, size, and age structure of conch within the park. Statistical models suggested that abundances of adults in 50 km of repeated towed-observer surveys had declined by 71% in 2016 relative to 2011. Further, the remaining conch populations were associated with tidal channels, and these model results agreed with independent observations in 40 km of expanded survey area. Measurements of shell lip thickness, an estimator of relative age, showed an increase relative to 1994 with the greatest effect in 2016, indicating senescence. The ECLSP population appears to be slowly dying of old age, and an early life history process has been altered. Upstream populations have been heavily fished while habitats within the park remain productive, suggesting that low local retention and a lack of exogenous larval sources are driving the decline. A network of MPAs encompassing the entire life cycle and dispersal envelope of targeted organisms is needed for proper conch conservation. Surveys focused on tidal channels could locate candidate upstream populations of conch.

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Section: Discussionmentioning

confidence: 99%

“…However, growth patterns and shell characteristics are influenced by the environment and are spatially and temporally variable. In The Bahamas, sexual maturity is first observed in conch with a shell lip thickness near 10 mm (Stoner et al 2012a), and 50% maturity occurs near 15 mm (Community Conch unpubl. data).…”

Section: Introductionmentioning

confidence: 99%

Efficacy of an established marine protected area at sustaining a queen conch Lobatus gigas population during three decades of monitoring

Kough¹,

Cronin²,

Skubel³

et al. 2017

Mar. Ecol. Prog. Ser.

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“…Animals were tagged across the size classes 'juvenile', 'subadult' and 'adult' in December 2009, June 2010and April 2011 (Table 1). Animals with syphonal length of <150 mm were considered juvenile, those >150 mm were considered subadult, and those with a well-developed shell lip were considered adult, following the classification of Peel & Aldana-Aranda (2012) and Stoner et al (2012). The size distribution of tagged animals reflects well the size distribution in the entire population (Peel & Aldana-Aranda 2012).…”

Section: Tagging and Trackingmentioning

confidence: 99%

A groundwater-fed coastal inlet as habitat for the Caribbean queen conch Lobatus gigas—an acoustic telemetry and space use analysis

Dujon¹

2017

Mar. Ecol. Prog. Ser.

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The queen conch Lobatus (Strombus) gigas, a marine snail, is among the most important fisheries resources of the Caribbean region. To provide effective protection in marine reserves, a good understanding of its habitat usage is essential. Queen conches commonly inhabit marine habitats. In this study, its activity space in a marginal estuarine-like habitat, the groundwater-fed inlet of Xel-Há (Mexico) was determined using high-resolution acoustic telemetry (VEMCO Positioning System). Thirty-eight animals with syphonal lengths ranging from 80 to 200 mm were tagged, 1 of them with an accelerometer tag. Their trajectories were recorded for 20 mo at 5 m resolution in a closely spaced array of 12 receivers. Space-time kernel home ranges ranged from 1000 to 18 500 m 2 with an ontogenetically increasing trend. Juveniles, subadults and most adults displayed continuous, non-patchy home ranges consistent with the typical intensive feeding activity by this fast-growing gastropod. In some adults, Lévy flight-like fragmentation of home ranges was observed that may be related to feeding range expansion or other ecological drivers such as the breeding cycle. The observed small home ranges indicate that the space use of queen conch in this estuarine-like habitat is not conditioned by food availability, and despite environmental stress due to daily low-oxygen conditions, space use is comparable to that observed in more typical marine habitats. In a marine reserve context, the groundwater-fed inlet provides adequate protection of this inshore queen conch population. Such marginal habitats may play an increasingly important role in conservation management as pressure on populations increase.

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“…from each gonad for histological preparation. Samples were prepared and mounted on glass slides according to the steps described by Stoner et al (2012a). All samples underwent histological analysis and were inspected for stages of gametogenesis, percent cover of gametogenic tissue and given a reproductive classification following procedures adapted from Delgado et al (2004).…”

Section: Whales and Dolphinsmentioning

confidence: 99%

Status and trends Saba Bank fisheries: 2015

Graaf¹,

Brunel²,

Nagelkerke³

et al. 2017

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Maturation and age in queen conch (Strombus gigas): Urgent need for changes in harvest criteria

Cited by 45 publications

References 29 publications

Efficacy of an established marine protected area at sustaining a queen conch Lobatus gigas population during three decades of monitoring

Efficacy of an established marine protected area at sustaining a queen conch Lobatus gigas population during three decades of monitoring

A groundwater-fed coastal inlet as habitat for the Caribbean queen conch Lobatus gigas—an acoustic telemetry and space use analysis

Status and trends Saba Bank fisheries: 2015

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