Assessing the scale and ecological impact of derelict and discarded fishing gear across Thailand via the MARsCI citizen science protocol.

South-East Asia is among the least studied regions for the growing issue of marine debris pollution, despite being a major contributor towards global marine debris. In the present study, we provide the preliminary results from the MARsCI project, a survey protocol designed to utilise citizen science to facilitate data collection on the ecological impact of discarded fishing gear (DFG) in Thailand. Over a three-year period, 103 surveys were carried out across Thailand, resulting in impact assessment of 606 pieces of DFG. Our findings indicate corals are regularly impacted by DFG in Thai waters and that isolated marine habitats may be more severely impacted than near-shore sites. We further identify crabs, muricid snails, and demersal fish to be among the most regularly entangled animals. We discuss our findings in the context of earlier work from Thailand, and conduct a critical review of the protocol itself, identifying improvements for future efforts.

A cup half full: the first assessment on the distribution, ecology and need for conservation of the threatened Neptune's cup sponge, Cliona patera, in the Gulf of Thailand.

The Neptune's cup sponge is an iconic species found in marine soft sediment habitats in the Indo-West Pacific, with a history of overharvesting and extreme population declines. Access to SCUBA diving surveys has allowed for its rediscovery at Singapore, its type locality; however, with fewer than ten living individuals documented in the twenty-first century, the species is believed to be in need of conservation. Here, we share the results from surveys across the Gulf of Thailand, allowing for a documentation of 29 additional individuals, with information on their ecology and distribution. Of the 29 individuals, extensive damage or mortality caused by marine debris is recorded for six individuals, and one further individual is believed to be lost due to an unknown cause. Documented threats from the Gulf of Thailand differ from those in Singapore; however, low population sizes and poor connectivity remain a significant concern for the survival of the species.

Dietary protein requirement for captive juvenile green turtles (Chelonia mydas).

Head-starting programs are extremely important for restoring the population of sea turtles in wild whereas husbandry conditions and feeding regimens of captive turtles are still limited. In the current study, the optimal dietary protein requirement for green turtle (Chelonia mydas) was investigated to support rearing in head-starting programs. Twenty-five-day-old turtles (44.5-46.2 g body weight, n = 45) were randomly distributed into 15 experimental plastic tanks, comprising three treatment replications of 3 turtles each. They were fed fishmeal-based feeds containing different levels of protein (30%, 35%, 40%, 45%, and 50%) for 8 weeks. At the end of feeding trial, growth performance (specific growth rate = 1.86% body weight/day) and feed utilization (protein efficiency ratio = 3.30 g gain/g protein) were highest in turtles fed with 40% protein in feed (p < .05). These nutritional responses were significantly supported by specific activities of fecal digestive enzymes, especially trypsin, chymotrypsin, amylase, and the amylase/trypsin ratio. Also, this dietary level improved the deposition of calcium and phosphorus in carapace, supporting a hard carapace and strong healthy bones. There were no negative effects in general health status of reared turtles, as indicated by hematological parameters. Based on a broken-line analysis between dietary protein levels and specific growth rate, the optimal protein level for green turtles was estimated as 40.6%. Findings from the current study support the use of artificial diets of specific protein levels to rear captive green turtle before release to natural habitats.

Optimal Feeding Frequency for Captive Hawksbill Sea Turtle (Eretmochelys imbricata).

Hawksbill sea turtle (Eretmochelys imbricata) has been reared in head-starting captivity programs, while the feeding regimens have never been optimized. In the current study, the feeding frequency of hawksbill sea turtle was investigated in indoor experimental conditions. Two-month-old turtles (38.98 ± 0.02 g) were distributed to triplicates of five treatments containing three turtles each and they were fed at different frequencies: one meal daily at 12.00 h (1M12), two meals daily at 08.00 and 12.00 h (2M8-12), two meals daily at 08.00 and 16.00 h (2M8-16), two meals daily at 12.00 and 16.00 h (2M12-16), or three meals daily at 08.00, 12.00 and 16.00 h (3M8-12-16). At the end of an 8-week trial, growth performance (specific growth rate 2.39 ± 0.02% body weight day-1) and feed consumption (feeding rate 2.00 ± 0.43 g day-1) were highest for turtles fed 2M8-16, followed by 2M12-16 or 3M8-12-16 relative to the other treatments (p ˂ 0.05). These treatments had significantly higher trypsin specific activity and trypsin/chymotrypsin ratio, and vice versa for lipase specific activity and amylase/trypsin ratio, relative to the remaining treatments. These match well with the fecal thermal properties that indicate amounts of available and unavailable nutrients present in the feces. Hematological parameters and carapace elemental composition showed no negative effects to turtles in 2M8-16 treatment. Therefore, two meals daily with long time interval were optimal for feeding hawksbill sea turtle. Findings from the current study could be directly used as a feeding guideline supporting the head-starting programs of this species.

Enrofloxacin and its major metabolite ciprofloxacin in green sea turtles (Chelonia mydas): An explorative pharmacokinetic study.

The present study aimed to assess the pharmacokinetic features of enrofloxacin (ENR) and its major metabolite, ciprofloxacin (CIP) in green sea turtles (Chelonia mydas) after single intravenous (i.v.) and intramuscular (i.m.) administration at two dosages of 5 and 7.5 mg/kg body weight (b.w.). The study used 10 animals randomly divided into equal groups. Blood samples were collected at assigned times up to 168 hr. The concentrations of ENR and CIP in turtle plasma were quantified by a validated high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The concentration of ENR in the experimental turtles with respect to time was pharmacokinetically analyzed using a noncompartment model. The concentrations of ENR in the plasma were quantified up to 144 hr after i.v. and i.m. administrations at dosages of 5 and 7.5 mg/kg b.w., whereas CIP was quantified up to 96 and 144 hr, respectively. The elimination half-life values of ENR were 38.7 and 50.4 hr at dose rates of 5 and 7.5 mg/kg b.w. after i.v. administration, whereas CIP was 33.6 and 22.6 hr, respectively. The maximum concentration (Cmax ) values of ENR were 2.07 and 2.59 µg/ml at dose rates of 5 and 7.5 mg/kg b.w., respectively. The value of area under the curve from 0 to 24 hr (AUC0-24 )/minimum inhibitory concentration (MIC) ratio of ENR was >125 for bacteria with MIC of 0.12 and 0.13 µg/ml after the administration of 5 mg/kg by i.m. and i.v. administration, respectively. Based on the pharmacokinetic data, susceptibility break-point and pharmacokinetic (PK)/pharmacodynamic (PD) indices, i.m. single administration of ENR at a dosage of 5 mg/kg b.w. might be clinically appropriate for treatment of susceptible bacteria in green sea turtles (Chelonia mydas).

Optimal Background Color for Head-Starting Northern River Terrapins (Batagur baska Gray, 1831).

Background color has significant effects on the lifestyles of various animal species. In this study, the effects of wall background color on growth, feed utilization, specific activity of gastric and pancreatic enzymes in fecal samples, fecal thermal properties, carapace elemental profile, and hematological parameters were investigated in northern river terrapin (Batagur baska Gray, 1831) in order to optimize the head-starting conditions. The terrapins (70.13 ± 0.04 g initial weight) were completely randomized into five types of colored tanks (transparent, green, red, blue, and black) and reared for twelve weeks. At the end of the experiment, tank color had no effect on survival and growth performance, but had significant effects on feeding rate, feed conversion ratio, and protein efficiency ratio (p < 0.05). Terrapins reared with black, red, or blue backgrounds had the highest feed utilization among the treatments. Among these three groups, analysis of specific activity of gastric and pancreatic enzymes in fecal samples and fecal thermal properties suggested improved digestive functionality in terrapins reared with a blue background relative to the other treatments. Carapace elemental composition and hematological parameters indicated no negative effects on health status of the terrapins reared with this optimal treatment. Findings from the current study support the head-starting program of northern river terrapins before release to natural habitats, and could also be applied in aquaria or zoos for public display.

5334000-53340000Optimal Salinity for Head-Starting Northern River Terrapins (Batagur baska Gray, 1831).

Northern river terrapins (Batagur baska Gray, 1831) are Asia's largest turtles living in both freshwater and brackish water. In the current study, the optimal salinity for head-starting programs of this critically endangered species was investigated in order to serve the well-being of turtles before release to natural habitat. Forty-eight terrapins (54.64 ± 0.18 g initial body weight) were randomly distributed to four salinity levels (0, 4, 8, and 12 ppt) and reared for eight weeks, using three replicates with four terrapins each. At the end of rearing trial, growth performance and feed utilization parameters were superior in terrapins reared at 4 ppt, followed by 8 ppt in the rank order of treatments. Negative stress responses were observed in terrapins reared at 12 ppt, as the fecal activity of amylase-to-trypsin ratio was changed significantly, but not that of proteolytic enzymes. The fecal thermal transition properties indicated an abundance of nutrients in the post-absorptive phase for terrapins reared at 4 ppt, followed by the 8 ppt treatment group. The preferred 4 ppt salinity had no negative effects on the health status of the terrapins in terms of carapace elemental composition or hematological parameters. Second-order polynomial regression suggests 4.35 ppt as the optimal salinity for maximal weight gain. Findings from the current study could be directly used in ex situ conservation programs of northern river terrapins before release to natural habitat.