THOUSANDS OF SINGLE NUCLEOTIDE POLYMORPHISMS IN THE CRITICALLY EN- DANGERED KEMP’S RIDLEY SEA TURTLE (LEPIDOCHELYS KEMPII) REVEALED BY DOU- BLE-DIGEST RESTRICTION-ASSOCIATED DNA SEQUENCING: OPPORTUNITIES FOR PREVIOUSLY ELUSIVE CONSERVATION GE- NETICS RESEARCH.—Among sea turtles, the Kemp’s ridley is the most endangered and geographically restricted, with its distribution mostly confined to the Gulf of Mexico (NMFS and USFWS, 2015). After experiencing a severe and sustained bottleneck that put this species on the verge of extinction, it appeared to be rebounding successfully, as evidenced by an exponential growth in the number of nests observed per nesting season, following decades of Mexico–United States bi-national efforts aimed at its recovery (Heppell et al., 2007). Unfortunately, nesting was severely reduced by ~35% during 2010 (the year of the BP Deepwa- ter Horizon oil spill in the Gulf of Mexico), as compared to nesting rates in 2009 (NMFS and USFWS, 2015). Although nesting rebounded during 2011 and 2012 to levels similar to that of 2009, nesting declined drastically again during 2013 and experienced a further drop during 2014 (NMFS and USFWS, 2015; Shaver et al., 2016). The number of nests in 2014 represents a 46% decrease from 2012, which was the year with the highest recorded number of nests since 1965 (Sarti, 2014). Should nesting continue to de- cline, long-term species recovery efforts will be compromised. Therefore, there is deep concern about the future of the Kemp’s ridley, and data to inform and assess bi-national management and conservation measures are urgently needed (Plotkin and Bernardo, 2014). Population ge- netics information crucial to the long-term conservation of the Kemp’s ridley, including baseline data required for monitoring its future status, is lacking. This includes estimations of genomic diversity, effective population size, and number of breeders; assessment of levels of population differentiation; and detection of genomic signatures of bottlenecks.
Gulf of Mexico
LONG-TERM MOVEMENTS OF AN ADULT MALE KEMP’S RIDLEY SEA TURTLE (LEPI- DOCHELYS KEMPII) IN THE NORTHWEST- ERN GULF OF MEXICO—Despite recent insights into the spatial ecology of juvenile (Morreale and Standora, 2005; Renaud and Williams, 2005; Mansfield, 2006; McClellan, 2009; Seney and Landry, 2011; Lyn et al., 2012) and postnesting female Kemp’s ridleys (Lepi- dochelys kempii) (Seney and Landry, 2008, 2011; Shaver and Rubio, 2008; Shaver et al., 2013, 2016), the breeding, migratory, and foraging behaviors of adult male Kemp’s ridleys remain largely unknown (Shaver et al., 2005).
The current paradigm suggests that adult male Kemp’s ridleys primarily reside in neritic forag- ing habitats near nesting beaches year round and engage in courtship and mating activities in March, immediately before the April–July nest- ing season (Owens, 1980; Rostal et al., 1998; Rostal, 1991, 2005; Shaver et al., 2005). Field observations of mounted pairs near known nesting beaches have occurred between October and May in Mexico (Rancho Nuevo) and in early June in Texas [Padre Island National Seashore (PAIS)], although confirmation of copulation is lacking (Pritchard and Ma ́rquez, 1973; Shaver et al., 2005). This tendency for male Kemp’s ridleys to establish year-round residency near nesting beaches is behaviorally disparate from seasonal migratory movements displayed by adult female conspecifics (Seney and Landry, 2008, 2011; Shaver and Rubio, 2008; Shaver et al., 2016; Hughes and Landry, unpubl. data) and males of other species (Lepidochelys olivacea: Beavers and Cassano, 1996; Plotkin et al., 1996; Caretta caretta: Arendt et al., 2012; Casale et al., 2013; Chelonia mydas: Limpus, 1993; Hays et al., 2001; Der- mochelys coriacea: James et al., 2005).
Identification of spatially and temporally defined areas frequented by adult male Kemp’s ridleys for breeding, migrating, or foraging is necessary to accomplish a Priority 1 Recovery Task in the Kemp’s Ridley Recovery Plan mandating protection and management of im- portant marine habitats (National Marine Fish- eries Service, 2011). Implementation of marine protected areas and other conservation measures to facilitate protection of adult males utilizing
critical habitats will require a comprehensive effort to better delineate habitat boundaries, assess localized sources of mortality, and, in foraging areas, to quantify and qualify prey resources and physical site characteristics. Infor- mation on adult male Kemp’s ridley migratory behavior is currently limited to a single source describing the movements of 11 individuals incidentally captured from waters near Rancho Nuevo (Shaver et al., 2005). Our analysis herein of a single adult male Kemp’s ridley’s long-term movements in northwestern Gulf of Mexico (GOM) waters, which recently have been identi- fied as critical foraging (Shaver et al., 2013) and migratory (Shaver et al., 2016) habitat for adult female conspecifics, is the longest time series of information to date for a male sea turtle. This study provides valuable insight into the behavior of an individual male Kemp’s ridley and has implications for the management and conserva- tion of the species.
We developed a Kemp’s ridley (Lepidochelys kempii) stock assessment model to evaluate the relative contributions of conservation efforts and other factors toward this critically endangered species’ recovery. The Kemp’s ridley demographic model developed by the Turtle Expert Working Group (TEWG) in 1998 and 2000 and updated for the binational recovery plan in 2011 was modified for use as our base model. The TEWG model uses indices of the annual reproductive population (number of nests) and hatchling recruitment to predict future annual numbers of nests on the basis of a series of assumptions regarding age and maturity, remigration interval, sex ratios, nests per female, juvenile mortality, and a putative ‘‘turtle excluder device effect’’ multiplier starting in 1990. This multiplier was necessary to fit the number of nests observed in 1990 and later. We added the effects of shrimping effort directly, modified by habitat weightings, as a proxy for all sources of anthropogenic mortality. Additional data included in our model were incremental growth of Kemp’s ridleys marked and recaptured in the Gulf of Mexico, and the length frequency of stranded Kemp’s ridleys. We also added a 2010 mortality factor that was necessary to fit the number of nests for 2010 and later (2011 and 2012). Last, we used an empirical basis for estimating natural mortality, on the basis of a Lorenzen mortality curve and growth estimates. Although our model generated reasonable estimates of annual total turtle deaths attributable to shrimp trawling, as well as additional deaths due to undetermined anthropogenic causes in 2010, we were unable to provide a clear explanation for the observed increase in the number of stranded Kemp’s ridleys in recent years, and subsequent disruption of the species’ exponential growth since the 2009 nesting season. Our consensus is that expanded data collection at the nesting beaches is needed and of high priority, and that 2015 be targeted for the next stock assessment to evaluate the 2010 event using more recent nesting and in-water data.
The history of the critically endangered Kemp’s ridley sea turtle (Lepidochelys kempii) has presented scientists and conservationists with a variety of questions and challenges originating in part from the species’ limited distribution and single primary nesting beach. Although the species was initially brought to the attention of the scientific community in 1880 by Richard Kemp, more than 80 yr passed before Henry Hildebrand revealed the location of its primary nesting beach at Rancho Nuevo, Mexico in the western Gulf of Mexico. By the time scientists began estimating the number of females nesting at Rancho Nuevo, it appeared that the species had declined when compared with the relatively large mass nesting (a.k.a. arribada) filmed by Andres Herrera in 1947. This decline appeared to be due to historic exploitation of turtles and their eggs on the nesting beach and accidental capture in the Gulf of Mexico shrimp fishery. Despite the implementation of conservation measures at Rancho Nuevo, the species continued to decline until the mid-1980s. The continued protection of females and nests on the nesting beach, the decline in shrimping effort in the Gulf of Mexico, and the implementation of turtle excluder devices resulted in a significant increase in the number of females nesting during the 1990s, and an exponential recovery rate. Since 2010, the recovery rate has unexpectedly deviated from its exponential trend and sharp declines have been documented in some years. The underlying cause(s) of the recent decline is unclear.
A review of the literature and examination of over 3,200 specimens of shallow water (<200 m) tropical western Atlantic (TWA) Drilliidae Olson, 1964 in museum and private collections has resulted in the recognition of numerous previously undescribed species, 100 of which are proposed here for the first time. A total of 65 names were found in the literature. Of these, 48 are considered valid, 16 synonyms, and one nomen dubium. In addition, characteristics that distinguish each genus currently in use for TWA shallow water species have indicated the need for reassignment (new combinations within Drilliidae) of 15 species. Some nomenclatural actions have come about from the literature review and include one taxon placed in junior synonymy (under an older name recently re-discovered) and one new name for a junior homonym. Two neotypes, five lectotype designations, and one new name are also proposed. Altogether, nomenclatural actions on 17% of valid previously described taxa are proposed. The 100 proposed names are placed in 12 available and one new genus: Agladrillia Woodring, 1928 (2), Bellaspira Conrad, 1868 (7), Calliclava McLean, 1971 (3), Cerodrillia Bartsch & Rehder, 1939 (11), Clathrodrillia Dall, 1918 (6), Decoradrillia, new genus (4), Douglassia Bartsch, 1934 (4), Fenimorea Bartsch, 1934 (15), Leptadrillia Woodring, 1928 (12), Lissodrillia Bartsch & Rehder, 1939 (8), Neodrillia Bartsch, 1943 (2), Splendrillia Hedley, 1922 (13), and Syntomodrillia Woodring, 1928 (13). These are the first reports of Calliclavain the western Atlantic, previously known only from the eastern Pacific. The new genus, Decoradrillia, is proposed to hold four new species and one existing that share a unique shell microsculpture and other morphological traits. One genus, Drillia Gray, 1838, is not currently believed to have TWA representatives. Three genera comprised exclusively of bathyal species are not treated in this work: Clavus Monfort, 1810 (=Eldridgea Bartsch, 1934), Globidrillia Woodring, 1928, and Spirotropis Sars, 1878. The significant increase in species within all of the genera has the effect of strengthening the groups’ diagnostic characters by their presence across a greater number of species. Each of the 148 valid species treated herein are described (or redescribed) and photographs of types presented, as are photographs of morphological variants and representatives from separate geographic areas, if available, to illustrate species’ variability
We recorded the first sighting and collection of the non-native, invasive red lionfish (Pterois volitans [Linnaeus, 1758]: Scorpaenidae) in the southern Gulf of Mexico, off the northern Yucatan Peninsula. In December 2009, two individuals were sighted (one of them speared) at 38 m depth over a reef formation, about 58 km northwest of the Alacranes Reef National Park, which is located 130 km off the northern coast of the Yucatan Peninsula, Mexico. More than 20 years after the introduction of P. volitans into the western Atlantic, specifically off the Florida and North Carolina coasts, the invasion circuit now appears to be closing in, since this new record was made about 800 km from the Dry Tortugas and Marquesas, Florida. This recording appears to be the first introgression of the P. volitans population into the Gulf of Mexico via larval transport.