New taxa described in Zoology in the Middle East

Abstract

The region between Mersin and ?skenderun was selected for studying marine turtles in the Turkish waters of the Mediterranean sea, as the most important nesting grounds of Green Turtles (Chelonia mydas) in the Mediterranean are situated there. In the 1995–96 fishing season, the 5 trawl boats taking part in the project reported that nets in the Eastern Mediterranean trapped 160 Green Turtles and 26 Loggerhead Turtles (Caretta caretta). In the following trawling season (1996/97), 306 Green Turtles, 116 Loggerhead Turtles (Caretta caretta) and 437 Nile Soft-shelled Turtles (Trionyx triunguis) were found to be trapped as a by-catch in the trawling nets. 87% of these turtles were captured by mid-trawling nets, the rest by bottom-trawling nets, mostly at depths of 11–30 m. 95% of all turtles were caught alive and healthy, and were usually released back into the sea immediately after capture by the fishermen. Training measures were given to local fishermen in order to raise their awareness of the threats to marine turtles.     

An interaction index to predict turtle bycatch in a Mediterranean bottom trawl fishery

Incidental catch is the major threat to the survival of loggerhead turtles (Caretta caretta) in the Mediterranean and the main reason for their decline. More than 100,000 turtles are estimated to be caught annually due to fishing practices; 10–50% die. Bottom trawls are among the fishing gears exerting the worst impact on sea turtle populations, especially in the coastal waters of Tunisia and Libya, northern Adriatic Sea, the Mediterranean coastal areas of Turkey and Egypt, where the continental shelf is large and turtles in the demersal stage are commonly found also in winter. Seven adult-sized loggerhead turtles captured incidentally by bottom trawls in the central-northern Adriatic Sea and treated in rescue centres were tagged with satellite transmitters before release. In this paper Italian bottom trawl track data obtained from vessel monitoring systems (VMSs) were analysed by VMSbase R suite to identify the areas of maximum fishing effort in the Adriatic. These data were combined with satellite information on turtle distribution to provide an interaction index enabling prediction of potential trawl–turtle interaction hotspots and periods. The present pilot study can be considered as a risk-analysis approach directed at identifying the areas and times of possible trawling–turtle interactions in a Mediterranean trawl fishery. By identifying the areas and seasons at highest risk of turtle bycatch, the index here developed has the potential to provide key information to design and implement mitigation strategies. Vessel monitoring system is actually in force in several countries, therefore the approach here studied might have a worldwide application.     

A first estimate of sea turtle bycatch in the industrial trawling fishery of Gabon

Gabon hosts nesting grounds for several sea turtle species, including the world’s largest rookery for the leatherback turtle (Dermochelys coriacea), Africa’s largest rookery for the olive ridley turtle (Lepidochelys olivacea) and smaller aggregations of the hawksbill turtle (Eretmochelys imbricata) and green turtle (Chelonia mydas). To assess the level of incidental captures of turtles by the Gabonese trawl fishery, an onboard observer program was conducted in the period 2012–2013. A total of 143 turtles were captured by 15 trawlers during 271 fishing days. The olive ridley turtle was the main species captured (80% of bycaught turtles), with mostly adult-sized individuals. The remaining 20% included green turtles, hawksbill turtles, leatherback turtles and undetermined species. Bycatch per unit of effort (BPUE) of olive ridley turtles varied greatly depending on the period of the year (range of means: 0.261–2.270). Dead and comatose turtles were 6.2 and 24.6% respectively (n = 65). By applying the available fishing effort to two BPUE scenarios (excluding or considering a seasonal peak), the total annual number of captures was estimated as ranging between 1026 (CI 95% 746–1343) and 2581 (CI 95% 1641–3788) olive ridley turtles, with a mortality ranging from 63 (CI 95% 13–135) to 794 (CI 95% 415–1282) turtles per year depending on the scenario and on the fate of comatose turtles. Such a potential mortality may be reason for concern for the local breeding population of olive ridley turtles and recommendations in terms of possible conservation measures and further research are given.     

Driftnet fishery threats sea turtles in the Atlantic Ocean

Fisheries are recognised as a major threat to sea turtles worldwide. Oceanic driftnets are considered the main cause of the steep decline in Pacific Ocean populations of the leatherback sea turtle Dermochelys coriacea. The world’s largest leatherback population nests in West Africa and migrates across the Atlantic Ocean to feed off the South American coast. There, the turtles encounter a range of fisheries, including the Brazilian driftnet fishery targeting hammerhead sharks. From 2002 to 2008, 351 sea turtles were incidentally caught in 41 fishing trips and 371 sets. Leatherbacks accounted for 77.3% of the take (n = 252 turtles, capture rate = 0.1405 turtles/km of net), followed by loggerheads Caretta caretta (47 individuals, capture rate = 0.0262 turtles/km of net), green turtles Chelonia mydas (27 individuals, capture rate = 0.0151 turtles/km of net) and unidentified hard-shelled turtles (25 individual, capture rate = 0.0139 turtles/km of net) that fell off the net during hauling. Immediate mortality (i.e., turtles that were dead upon reaching the vessel, excluding post-release mortality) was similar among the species and accounted for 22.2 to 29.4% of turtles hauled onboard. The annual catch by this fishery ranged from 1,212 to 6,160 leatherback turtles, as estimated based on bootstrap procedures under different fishing effort scenarios in the 1990s. The present inertia in law and enforcement regarding gillnet regulations in Brazil could result in the reestablishment of the driftnet fishery, driving rates of leatherback mortality to levels similar to those observed in previous decades. This development could potentially lead to the collapse of the South Atlantic leatherback population, mirroring the decline of the species in the Pacific. In light of these potential impacts and similar threats to other pelagic mega fauna, we recommend banning this type of fishery in the region.     

Developing ultraviolet illumination of gillnets as a method to reduce sea turtle bycatch

Fisheries bycatch of marine animals has been linked to population declines of multiple species, including many sea turtles. Altering the visual cues associated with fishing gear may reduce sea turtle bycatch. We examined the effectiveness of illuminating gillnets with ultraviolet (UV) light-emitting diodes for reducing green sea turtle (Chelonia mydas) interactions. We found that the mean sea turtle capture rate was reduced by 39.7% in UV-illuminated nets compared with nets without illumination. In collaboration with commercial fishermen, we tested UV net illumination in a bottom-set gillnet fishery in Baja California, Mexico. We did not find any difference in overall target fish catch rate or market value between net types. These findings suggest that UV net illumination may have applications in coastal and pelagic gillnet fisheries to reduce sea turtle bycatch.     

An overview of loggerhead sea turtle (<Emphasis Type="Italic">Caretta caretta</Emphasis>) bycatch and technical mitigation measures in the Mediterranean Sea

This paper reviews the gear parameters responsible for loggerhead sea turtle (Caretta caretta) capture and mortality while taking into account the mitigation measures tested in the Mediterranean Sea. Incidental catch is considered as one of the major threats for turtle survival; however, the loggerhead bycatch estimated in different areas seems to be unrealistic, which highlights the need of a method for homogenising the estimates. Drifting longlines and bottom trawls have the greatest impact on Mediterranean turtle populations, respectively in pelagic and demersal phase, while passive nets (gillnets and trammel nets) seem to be responsible for the highest direct mortality, due to drowning. Most of the experiments available for the Mediterranean are focused on drifting longline. The longline parameters, hook shape and size, bait type, setting position and the reaction to sensory stimuli, strongly affect the sea turtle bycatch and mortality. Circle hooks have the potential to reduce turtle mortality only in certain fisheries and areas; larger hooks are less likely to be swallowed by turtles due to physical constraints of the mouth, reducing the mortality rate and the catch of juveniles; branchlines, once ingested, appear to be one of the major causes of sea turtle mortality; squid bait, which consistently catches more turtles than mackerel, and lightsticks, which strongly attract turtles, should be banned, at least in some areas and seasons. On the contrary only two bottom trawl studies are available from the Mediterranean. Turtle excluder devices have been tested with promising results in Turkey and Italy, even if the loss of large fish should be carefully investigated. For set nets no practical solutions are available at this time. The analysis allows the conclusion that technical parameters affecting turtle bycatch and mortality should only be studied one at a time, in order to avoid inconclusive results, studies on post-release mortality should be implemented and finally fishermen cooperation is paramount in reducing turtle bycatch and mortality.     

Long-term trends in abundance of green sea turtles (Chelonia mydas) assessed by non-lethal capture rates in a coastal fishery

Sea turtle populations underwent severe decline in historical times, mainly through harvesting eggs and adults on nesting beaches. With the reduction of this threat in many areas, coupled with other conservation actions, some populations have demonstrated encouraging recovery, although remaining below their previous levels and undergone additional modern threats such as incidental capture in fisheries and pollution. Trends in sea turtle populations have usually been assessed through monitoring of females or nests on nesting beaches. Here we present data from a 22-year monitoring period for a juvenile green sea turtle Chelonia mydas mixed-stock in southeastern Brazil that were incidentally captured in passive non-lethal pound nets. A total of 3639 green turtles were captured in 5323 fishing days.pound⁻¹ with mortality rate of 2%. Captures occurred in all months, but bycatch rates, excluding recapture events, were higher in September and October, probably due to the recruitment of turtles migrating from southern areas, as well as recruits from the oceanic zone. Capture rates increased by 9.2% per year in the period from 1995 to 2016, in line with increasing source populations, particularly the main source contributor at Ascension Island, but also Trindade Island (Brazil) and Aves Island (Venezuela). Mean Curved Carapace Length of green turtles was higher during austral summer/early autumn and decreased markedly in May, probably due to the small-sized individuals that recruited to the study site. We show that the incidental capture of sea turtles in non-lethal fisheries, such as Brazilian pound nets, could also provide data on trends of populations nesting in distant places, and can contribute to the assessment of population status of sea turtles within Regional Management Units throughout the Atlantic Ocean.     

Comparing Trawl and Creel Fishing for Norway Lobster (Nephrops norvegicus): Biological and Economic Considerations

This study compares the fishing activity and landings of the trawl and creel fisheries for Norway lobster (Nephrops norvegicus (L.)) off the Portuguese coast, and evaluates the financial viability of two vessels typical of each fleet. Crustacean trawlers are part of an industrial fleet that, besides Nephrops, targets deep water shrimps. Creels are used by a multi-gear, multi-target artisanal fleet, fishing only in areas unavailable to trawlers and, when catching Nephrops, set specifically to target this species. Trawlers have in recent years contributed with 85% of the landings in weight, but only 74% in value (2005-2009 average). Despite smaller landings, the Nephrops creel fishery provides individuals of larger size and in better condition, thereby obtaining higher unit prices. Economic viability was also higher for the creel vessel, with trawling being only viable if major costs (such as labor and fuel) are covered by the revenue from other target species (e.g., the rose shrimp). At present, Nephrops populations on the South and SW coast are subject to intense fishing and to a recovery plan. The possibility of reallocation of some of the fishing effort directed at Nephrops from trawlers to creels is discussed in terms of the conservation of the resource and economic return.     

The deep-water coral Lophelia pertusa in Norwegian waters: distribution and fishery impacts

The paper presents documentation on the distribution of, and damages to, deep-water reefs of the coral Lophelia pertusa in Norwegian waters. The reef areas have traditionally been rich fishing grounds for long-line and gillnet fisheries, and the coral habitat is known to support a high diversity of benthic species. Anecdotal reports claim that trawlers often use the gear, wires, chains and trawl doors to crush the corals and clear the area before fishing starts. To get an overview of the situation, information about the distribution and damage were collected from the literature, fishermen, and our own investigations. The results show that the corals are abundant particularly on the mid Norwegian continental shelf between 200 and 400 m depth. In general it seems that the largest densities are distributed along the continental break and at ridges of morainic origin. The reports from fishermen suggested severe damage to the corals and in situ observations using ROV confirmed the presence of mechanically damaged corals located on trawling grounds. A first estimate of the fishery impact indicates that between 30 and 50% of the reef areas are damaged or impacted. Fishermen claim that catches are significantly lowered in areas where the reefs are damaged. Potential ecological consequences of the destruction are discussed.     

Conservation Hotspots for the Turtles on the High Seas of the Atlantic Ocean

Understanding the distribution of bycaught sea turtles could inform conservation strategies and priorities. This research analyses the distribution of turtles caught as longline fisheries bycatch on the high seas of the Atlantic Ocean. This research collected 18,142 bycatch observations and 47.1 million hooks from large-scale Taiwanese longline vessels in the Atlantic Ocean from June 2002 to December 2013. The coverage rates were ranged from 0.48% to 17.54% by year. Seven hundred and sixty-seven turtles were caught, and the major species were leatherback (59.8%), olive ridley (27.1%) and loggerhead turtles (8.7%). Most olive ridley (81.7%) and loggerhead (82.1%) turtles were hooked, while the leatherbacks were both hooked (44.0%) and entangled (31.8%). Depending on the species, 21.4% to 57.7% were dead when brought onboard. Most of the turtles were caught in tropical areas, especially in the Gulf of Guinea (15°N-10°S, 30°W-10°E), but loggerheads were caught in the south Atlantic Ocean (25°S-35°S, 40°W-10°E and 30°S-40°S, 55°W-45°W). The bycatch rate was the highest at 0.030 per 1000 hooks for leatherbacks in the tropical area. The bycatch rates of olive ridley ranged from 0 to 0.010 per thousand hooks. The loggerhead bycatch rates were higher in the northern and southern Atlantic Ocean and ranged from 0.0128 to 0.0239 per thousand hooks. Due to the characteristics of the Taiwanese deep-set longline fleet, bycatch rates were lower than those of coastal longline fisheries, but mortality rates were higher because of the long hours of operation. Gear and bait modification should be considered to reduce sea turtle bycatch and increase survival rates while reducing the use of shallow hooks would also be helpful.     

Molecular resolution of marine turtle stock composition in fishery bycatch: a case study in the Mediterranean

Based on an extensive sampling regime from both nesting populations and bycatch, frequency analyses of mitochondrial (mt) DNA control region haplotypes in the Mediterranean were used to assess the genetic structure and stock composition of the loggerhead sea turtle, Caretta caretta, in different marine fisheries. The analyses show the following. (i) In drifting longline fisheries working in Mediterranean pelagic habitats 53–55% of turtles caught originated from the Mediterranean stock; (ii) In bottom-trawl fisheries all turtle bycatch is derived from this regional stock; (iii) This regional stock contribution to fishery bycatch suggests that the population size of the Mediterranean loggerhead nesting population is significantly larger than previously thought. This is consistent with a recent holistic estimate based on the discovery of a large rookery in Libya. (iv) Present impact of fishery-related mortality on the Mediterranean nesting population is probably incompatible with its long-term conservation. Sea turtle conservation regulations are urgently needed for the Mediterranean fisheries. (v) The significant divergence of mtDNA haplotype frequencies of the Turkish loggerhead colonies define this nesting population as a particularly important management unit. Large immature and adult stages from this management unit seem to be harvested predominantly by Egyptian fisheries. (vi) Combined with other data, our findings suggest that all the nesting populations in the Mediterranean should be considered as management units sharing immature pelagic habitats throughout the Mediterranean (and possibly the eastern Atlantic), with distinct and more localized benthic feeding habitats in the eastern basin used by large immatures and adults. (vii) Between the strict oceanic pelagic and the benthic stages, immature turtles appear to live through an intermediate neritic stage, in which they switch between pelagic and benthic foods.     

Risk analysis reveals global hotspots for marine debris ingestion by sea turtles

Plastic marine debris pollution is rapidly becoming one of the critical environmental concerns facing wildlife in the 21st century. Here we present a risk analysis for plastic ingestion by sea turtles on a global scale. We combined global marine plastic distributions based on ocean drifter data with sea turtle habitat maps to predict exposure levels to plastic pollution. Empirical data from necropsies of deceased animals were then utilised to assess the consequence of exposure to plastics. We modelled the risk (probability of debris ingestion) by incorporating exposure to debris and consequence of exposure, and included life history stage, species of sea turtle and date of stranding observation as possible additional explanatory factors. Life history stage is the best predictor of debris ingestion, but the best‐fit model also incorporates encounter rates within a limited distance from stranding location, marine debris predictions specific to the date of the stranding study and turtle species. There is no difference in ingestion rates between stranded turtles vs. those caught as bycatch from fishing activity, suggesting that stranded animals are not a biased representation of debris ingestion rates in the background population. Oceanic life‐stage sea turtles are at the highest risk of debris ingestion, and olive ridley turtles are the most at‐risk species. The regions of highest risk to global sea turtle populations are off of the east coasts of the USA, Australia and South Africa; the east Indian Ocean, and Southeast Asia. Model results can be used to predict the number of sea turtles globally at risk of debris ingestion. Based on currently available data, initial calculations indicate that up to 52% of sea turtles may have ingested debris.     

Commercial harvest and export of snapping turtles (Chelydra serpentina) in the United States: trends and the efficacy of size limits at reducing harvest

As Asian turtle populations have crashed, China has increasingly turned to international import to meet domestic demand, which has increased pressure on global turtle populations. Snapping turtles (Chelydra serpentina) are being harvested in unprecedented numbers in the United States (US) to meet the needs of this international market. Here we report US snapping turtle live export from 1999 to 2013, and for the first time test the effectiveness of size limits in reducing commercial harvest numbers. Over three million live snapping turtles from farm and wild caught stock were exported from the US to Asia in 2012–14 alone. Increases in the export of wild caught snapping turtles to over 200,000 individuals in 2012 and 2014, compared to under 50,000 in other years, may indicate that farms are becoming unable to keep up with increasing demand. Annual harvest pressure at the state level increased linearly from 1998 to 2013, mirroring trends in federal export over the same time period. Our model estimates that size-limits were effective at reducing harvest by 30–87% in years with high harvest pressure. However, the majority of size limit regulations result in the removal of larger breeding adults, which has been shown to be detrimental to long term population viability. Regulatory approaches dedicated to the long term management of this iconic species will need to balance the short term gains, in the form of reduced harvest rates, with long term population viability.     

First records of dive durations for a hibernating sea turtle

The first published record, from the early 1970s, of hibernation in sea turtles is based on the reports of the indigenous Indians and fishermen from Mexico, who hunted dormant green turtles (Chelonia mydas) in the Gulf of California. However, there were no successful attempts to investigate the biology of this particular behaviour further. Hence, data such as the exact duration and energetic requirements of dormant winter submergences are lacking. We used new satellite relay data loggers to obtain the first records of up to 7h long dives of a loggerhead turtle (Caretta caretta) overwintering in Greek waters. These represent the longest dives ever reported for a diving marine vertebrate. There is strong evidence that the dives were aerobic, because the turtle surfaced only for short intervals and before the calculated oxygen stores were depleted. This evidence suggests that the common belief that sea turtles hibernate underwater, as some freshwater turtles do, is incorrect.     

Determinants of temporal trends in size in vessel-based reporting in the USA Illex illecebrosus fishery

The Illex illecebrosus fishery in the northwestern Atlantic Ocean is a trawl‐based fishery. Illex illecebrosus normally lives <1 year, thus managing the fishery using a standard stock assessment approach is difficult. Real‐time management is an attractive option. The purpose of this study was to investigate the utility of data on size composition reported by commercial vessels for application in real‐time management in the I. illecebrosus fishery. Observations were collected from fish processors for 1996–98 and from fishing vessels directly reporting in 1999–2001. Mean size of I. illecebrosus increased more or less steadily through the fishing season in each year. Apparent growth rates, determined by evaluating the change in mean size in the catch, varied considerably between years. Apparent growth rates appear to be reasonable expressions of true growth rates because either the bulk of the squid entered the fishery at the beginning of the fishery and remained with the fishery for the duration of the season, or the squid on the outer shelf, available to the fishery, represented an emigrated portion of a larger coherent offshore population. Depth exerted only a minor influence on the size of squid caught, whereas the size–frequency varied significantly with latitude. Largest squid were caught at the southern and northern extremes of the study domain. Refrigerated seawater (RSW) trawlers consistently caught smaller squid than did freezer trawlers. The complexity of I. illecebrosus size structure revealed by this study indicates the necessity of obtaining a dispersed data set, in space, with a degree of temporal detail to elucidate trends. Such a data set is conceivably obtainable from fishing vessels reporting information as they fish providing that the sampling design addresses issues concerning the dispersion of vessels across latitude, the appropriate composition of the reporting fleet, and the collection of sufficient observations per tow to adequately resolve the range in size as well as the mean.     

Relationship between the major phosphorylated metabolic intermediates and oxygen affinity of whole blood in the loggerhead (Caretta caretta) and the Green Sea Turtle (Chelonia mydas) during development.

(1) 2,3-Diphosphoglyceric acid (2,3-DPG) is present in the erythrocytes (RBC) of the 68-day loggerhead turtle embryo and 44-day green sea turtle embryo at levels of 7.4 and 5.5 μmoles/ml of RBC, representing the major organic phosphate during the latter period of embryonic development. (2) Inositol pentaphosphate (IPP) is absent in the red blood cells of the embryos of both the loggerhead and green sea turtle. (3) Near equimolar amounts of 2,3-DPG and IPP are present in the erythrocytes of the adult loggerhead and green sea turtle. The total concentration of these two organic phosphates is approximately 0.75 μmoles/ml of RBC in the adult of both species. (4) There is a switch from embryonic to adult hemoglobin during development of these two species of turtles; the two embryonic bands have identical electrophoretic mobilities, whereas the two adult bands migrate differently on cellulose acetate at pH 8.6. (5) The whole blood oxygen affinity of the adult loggerhead and green sea turtle is 60.3 and 32.6 Torr, respectively. (6) The stripped adult hemoglobins in these two species of turtles show no change in oxygen affinity upon addition of 2,3-DPG, ATP, or IPP. (7) It therefore appears unlikely that whole blood oxygen affinity is controlled by organic phosphate modulation of hemoglobin function in these species of turtles.     

Competition between the krill fishery and penguins in the South Shetland Islands

Among the South Shetland Islands, the potential competition for krill (Euphausia superba) between the Japanese fishery and krill-eating breeding penguins was assessed. A low level of competition was apparent due to several factors. Spatial overlap between the main fishing and foraging areas was insignificant. Firstly, the large colonies of the dominant penguin (chinstrap penguins,Pygoscelis antarctica) occurred where sea ice disappears early in spring, and not necessarily where krill are abundant in summer, i.e. the area of krill fishery. Secondly, overlap between trawling depth and foraging dive depth of penguins was marginal, with the latter depth being shallower. Moreover, overlap in the size-frequency of krill caught by trawlers and those captured by penguins was not complete; the penguins took larger krill on average. Finally, the present small fishery is unlikely to impact upon local krill biomass in the region. Krill biomass was estimated to be 250–1500 × 10³ tonnes within the preferred fishing areas during summer. The present catch rate by the fishery (≤13 × 10³ tonnes/half-month period) is smaller by an order of magnitude, and the fishing area does not include the main foraging areas of breeding penguins.     

广州市花地湾市场龟鳖类调查

通过对广州市花地湾花鸟鱼虫市场贸易龟鳖类进行为期3年27次调查,共记录了9科29属41种或亚种,包括鳖科(Trionychidae)2属2种,两爪鳖科(Carettochelyidae)1属1种,龟科(Emydidae)4属5种,淡水龟科(Geoemydidae)10属18种,侧颈龟科(Chelidae)3属3种,动胸龟科(Kinosternidae)2属3种,鳄龟科(Chelydridae)2属2种,陆龟科(Testudinidae)4属6种,海龟科(Cheloniidae)1属1种。其中,国内龟鳖类共13种,外来物种共28种。受保护种类30种,所占比例达73.17%,部分龟类来源为野外捕捉。大量实体商家转入互联网进行精确营销,尤其是针对高价值的濒危种类,未来将着重对该隐蔽领域进行深入调查。     

Importance of discards of a beam trawl fishery as input of organic matter into nursery areas within the Tagus estuary

The brown-shrimp beam trawl fishery carried out within the Tagus estuary produces discards due to the little commercial interest of most of the species caught. Between 1994 and 1996, monthly samples were collected in the two major fishing areas within the Tagus estuary, using a beam trawl, in order to estimate the amount of fish and crustaceans caught per unit of effort. The fishing effort of the commercial fleet was determined based on surveys of professional fishermen. Mortality estimates of discards were also evaluated experimentally. The main fish and crustacean species discarded after capture were Crangon crangon (Linnaeus, 1758), Liza ramada (Risso, 1826), Carcinus maenas (Linnaues, 1758) and Pomatoschistus minutus (Pallas, 1770). The estimated total amount of fishery discards in the upper part of the Tagus estuary is approximately 1500 tonnes per year, which represents ca. 90% of the captures. The mortality rate of the fishes and crustaceans discarded varied according to species and season, with the highest rates during Summer months. Considering nitrogen and carbon content of the main discarded species, an input of particulate organic matter of more than 140 tonnes of carbon and 35 tonnes of nitrogen per year were estimated for these estuarine areas.