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

Abstract

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.

The potential of marginal coastal nursery habitats for the conservation of a culturally important Caribbean marine species

“…Connected to the Caribbean Sea by a 100 m wide channel, the inlet is ~1 km long, covers an area of ca. 110 000 m 2 and has a maximum depth of 3.5 m (Stieglitz & Dujon, , Figure a). A persistent inflow of low‐salinity groundwater maintains a permanent thermohaline stratification throughout the year, with salinity on the bottom ranging from 10 to 35 (Back et al, ; Stieglitz & Dujon, ).…”

“…The grey square represents the receiver defined as the root of the tree. Figure modified from Stieglitz and Dujon ()…”

“…The queen conch is also observed outside its optimal niche in habitats such as groundwater‐fed coastal areas which are characterized by large variations in salinity and dissolved oxygen concentration (i.e. stressful for stenohaline species) and which are considered to be marginal for species typically found in fully marine habitats (Dujon, Stieglitz, Amice, & Webber, ; Stieglitz & Dujon, ; Stoner, ). Along the Yucatan Peninsula coastline (Mexico), an extensive underground cavern system channels water to coastal lakes, lagoons and submarine springs over the majority of the north‐west Yucatan coast (Figure ) and which accounts for >99% of the freshwater input in the area (Back, Hanshaw, Pyle, Plummer, & Weidie, ; Beddows, Smart, Whitaker, & Smith, ; Perry, Velazquez‐Oliman, & Marin, ).…”

“…stressful for stenohaline species) and which are considered to be marginal for species typically F I G U R E 1 (a) Location of Xel-Há inlet (Yucatan peninsula, Mexico) in the Caribbean Sea, (b) Geographical distribution of the groundwater-fed coastal habitats (in red) along the north-eastern coast of the Yucatan Peninsula. The black polygons indicate the marine protected areas, the blue polygons the presence of freshwater, brackish lakes or lagoons located less than 20 km from the coastline and the green dots the locations in which the presence of queen conch has been documented with from North to South: (1) Isla Mujeres (Tello-Cetina, Rodríguez-Gil, & Rodríguez-Romero, 2005), (2) Cozumel Island (Lozano-Álvarez & Briones-Fourzán, 2007), (3) Xel-Há inlet (Stieglitz & Dujon, 2017, this study), (4) Sian Ka'an Biosphere Reserve (Mazzotti et al, 2005) and (5) Banco Chinchorro (Tello-Cetina et al, 2005). The location of lakes and lagoons was obtained from Gondwe et al (2010) found in fully marine habitats (Dujon, Stieglitz, Amice, & Webber, 2019;Stieglitz & Dujon, 2017;Stoner, 2003).…”

Ecological spillover from a marine protected area replenishes an over‐exploited population across an island chain

“…Caribbean populations of L. gigas are isolated by larval dispersal (Truelove et al, 2017) and once local populations become depleted they are slow to rebound (Glazer & Delgado, 2003;Glazer, unpublished). Other than their larval phase, L. gigas are relatively sedentary, with home ranges on the scale of 10,000 m 2 (Doerr & Hill, 2013;Stieglitz & Dujon, 2017), thus MPAassociated replenishment of outside areas is directly through the ecological process of larval spillover.…”