Ontogenetic habitat shifts affect performance of artificial shelters for Caribbean spiny lobsters

Abstract

Early benthic juveniles (EBJ) of Caribbean spiny lobster Panulirus argus dwell solitarily in vegetated habitats but eventually shift to dwelling gregariously in crevice shelters ('crevices'). This habitat shift may depend on the interplay between the refuge value of the local vegetation (which increases with complexity) and that of available crevices (which increases with the potential they offer for gregariousness). We examined how these factors influenced density enhancement of lobsters with large artificial shelters ('casitas', 1.1 m 2 in refuge area) in a coastal reef lagoon. We deployed 10 casitas at each of five 1 ha sites, 3 located in the mid-lagoon zone (ML) and 2 in the back-reef lagoon zone (BRL). These zones differed in vegetation complexity and abundance of algal-dwelling EBJ (greater in the ML), and abundance of crevices (greater in the BRL). Over 4 yr (22 surveys), abundance of large juveniles (> 20 mm carapace length, CL) was initially higher in casitas in the BRL but tended to converge over time between lagoon zones, whereas EBJ (≤20 mm CL) were consistently more abundant in casitas in the BRL. Even when controlling for a potentially stronger conspecific chemical attraction exerted by greater aggregations of large juveniles in BRL casitas, significantly more EBJ shifted to casitas in the BRL than in the ML. Thus, lobster density enhancement with casitas was more immediate in the BRL, where the local vegetation ceased to protect lobsters sooner, but increased over time in the more lushly vegetated ML as gradually more lobsters shifted to, and persisted in, casitas.

Influence of local habitat features on disease avoidance by Caribbean spiny lobsters in a casita-enhanced bay

“…small isolated coral heads and rocks) occurred in areas nearer to the coral reef habitat. Yet, where casitas are available, lobsters tend to forgo small shelters in favor of casitas (Lozano-Álvarez et al 2009) because the large refuge area provided by casitas increases the potential for gregariousness and hence the benefit of group defense (Eggleston & Lipcius 1992, Mintz et al 1994, Briones-Fourzán et al 2007. Similarly, in habitats where unusually large natural crevices occur, these crevices typically contain the majority of lobsters (Butler & Herrnkind 1997).…”

Artificial shelters and marine infectious disease: no detectable effect of the use of casitas to enhance juvenile Panulirus argus in shelter-poor habitats on a viral disease dynamics

“…In the back-reef lagoon, seagrass meadows have generally less biomass, shorter leaves, and a less dense canopy because the sediment layer is thinner and hard substrate is more abundant ( van Tussenbroek, 2011 ; Zarco-Perelló & Enríquez, 2019 ). Biomass of drift algae tends to be greater on the mid-lagoon than on the back-reef lagoon zone ( Van Tussenbroek, 2011 ; Lozano-Álvarez, Meiners & Briones-Fourzán, 2009 ). Although the reef lagoon constitutes a nursery area for juveniles of P. argus (≤50 mm CL), shelter is a limiting factor for the larger juveniles ( Briones-Fourzán et al, 2007 ) because crevice-type shelter is scarce and over-dispersed in the reef lagoon ( Briones-Fourzán & Lozano-Álvarez, 2001 ).…”

“…1 ). Each site measured 100 m ×100 m (= 1 ha), an area that exceeds the daily home range of juveniles of P. argus (<1 to ∼20 m) ( Butler, Steneck & Herrnkind, 2006 ; Lozano-Álvarez, Meiners & Briones-Fourzán, 2009 ). To ensure the independence of data, all sites were separated from each other and from the reef tract by distances of 200 m to 600 m, which exceed the movement range of juveniles ≤70 mm CL ( Briones-Fourzán et al, 2007 ).…”

Climate change mitigation by coral reefs and seagrass beds at risk: How global change compromises coastal ecosystem services

“…This increase in sediment instability can exacerbate sea level rise by causing a further deepening of the bay and by reducing the amount of wave attenuation occurring within the subtidal region, which ultimately increases the vulnerability of the surrounding shoreline to erosion and coastal flooding (Quataert et al, 2015;Siegle and Costa, 2017;James et al, 2019bJames et al, , 2020bVenancio et al, 2020). Furthermore, an unstable sediment surface is likely to be uninhabitable for many currently existing benthic species within natural tropical bays, such as calcifying algae, urchins and juvenile lobster (Lozano-Álvarez et al, 2009). The benthic community has been shown to be tightly linked to the presence or absence of seagrass (Lundquist et al, 2018;Seitz and Ewers Lewis, 2018;Cadier and Frouws, 2019;Githaiga et al, 2019).…”