Natural Food Availability Research Articles

Spatiotemporal Variations in Trace Element Compositions in Pollock Populations under the Influence of Coastal Norwegian Salmon Farms

AbstractPollock Pollachius virens (also known as Saithe) modify their feeding habits when including in their diet uneaten feed pellets from salmon aquaculture sea cages. To determine the influence of salmon farms on Pollock, multivariate and univariate analyses were conducted on the trace element signatures from muscle and liver tissues. Sample fish were caught in the vicinity of salmon farms and in control areas (>3‐km distance from the farms) on the coast of Hitra Island (western Norway) over two consecutive years (2012 and 2013). The hepatosomatic index was calculated as a proxy of fish body condition and was higher in Pollock captured near the salmon farms in both years. Variations in specific trace element profiles revealed the influence of farming on the Pollock assemblages (i.e., arsenic, manganese, and copper in muscle; vanadium and manganese in liver). Differences in element composition between sampling years were notable and may, in addition to influence from salmon feed, reflect temporal variation in Pollock migrations or natural food availability. Multivariate analyses of each sampling year showed significant differences in trace element composition of both tissue types among the Pollock groups. Therefore, trace element assessment is a potential tool for determining the influence of aquaculture on Pollock populations, although other natural sources of variation must be taken into account when considering future aquaculture and fishery management strategies.

PENYULUHAN PEMANFAATAN LIMBAH BUDIDAYA IKAN GABUS (channa striata) PADA BUDIDAYA CACING SUTRA (Tubifex SP.) SEBAGAI PAKAN ALAMI BIBIT IKAN PADA POKDAKAN MAJU BERSAMA MESUJI, DESA SUNGAI BADAK, KECAMATAN MESUJI KABUPATEN MESUJI

The progress of the fish farming business, from hatchery to enlargement, is increasing from time to time. It can be seen from the increasing interest. The type of fish farming that is mostly carried out is the type of freshwater fish cultivation accompanied by technology that continues to develop. The role of natural feed as one of the determining factors for the success of fish hatchery businesses is often an obstacle because most cultivating communities still depend on natural products. Availability of natural food is important considering the mouth opening of fish larvae is small while the size of the feed that is not suitable is often a factor in the occurrence of premature death in the cultivation process. In addition, the amount of artificial feed that is not consumed by fish has the potential to damage the quality of the waters in the culture containers. Silk worms are an important natural feed in supporting fish hatcheries, freshwater fish are a determinant of the success of hatchery businesses both in terms of quality and quantity. Knowledge about silk worms is still very little known to the public. The result of this dedication is expected. The Pokdakan Maju Together with Mesuji, can utilize the waste of snakehead fish cultivation as a medium for the cultivation of silk worms (Tubifex sp.). Keywords: Freshwater Fish, Silk Worms, Natural Food

Feasibility Study of Green Mussel Perna viridis Farming in the Southeast Coast of the Bay of Bengal of Bangladesh

Green mussel farming in coastal waters is on the edge of aquaculture trends for its worldwide acceptability as a supreme delicacy and an inexpensive protein source. The coastal water of Bangladesh has one of the world’s richest ecosystems with high productivity of fisheries due to the geographical location in the tropical climate zone, high rainfall and enrichment of water nutrients through the surface of the wide Gangetic river systems. This study aims to assess the feasibility of green mussel ( Perna viridis ) culture in the southeast coast of the Bay of Bengal, emphasizing coastal landlocked channels and estuary. Site capability rating system was applied based on the biophysical parameters and natural food requirements for the fast and effective evaluation of potential sites of green mussel farming. The year-round monthly variations of environmental parameters and plankton composition were recorded from seven potential sites Moheshkhali Channel, Rezu Khal and Naf River. Based on the biophysical parameters, Rezu Khal area is ranked as unsuitable/less suitable for green mussel culture mainly due to shallow water depth, high turbidity, lower food availability and higher temporal salinity fluctuation caused by the freshwater run-off during the monsoon season. However, Moheshkhali Channel and Naf River are medium to good sites based on suitability rating points, indicating that these sites are most suitable for commercial green mussel farming. Moreover, high chlorophyll-α and plankton abundance in these sites ensure that natural food availability is adequate to sustain green mussel farming. The present study findings would be applicable for the planning and development of a sustainable green mussel farming system in Bangladesh and elsewhere.

Urbanisation weakens selection on the timing of breeding and clutch size in blue tits but not in great tits

Urbanisation is a globally occurring phenomenon and is predicted to continue increasing rapidly. Urban ecosystems present novel environments and challenges which species must acclimate or adapt to. These novel challenges alter existing or create new selection pressures on behaviours which provide an opportunity to investigate eco-evolutionary responses to contemporary environmental change. We used 7 years of breeding data from urban and forest populations of blue and great tits to understand whether selection for timing of breeding or clutch size differed between the two habitats and species. We found that urban great tits laid eggs earlier than their forest counterparts, but there was no evidence of a difference in selection for earlier breeding. Blue tits, however, did not differ in timing of egg laying between the two habitats, but selection for earlier laying was weaker in the urban environment. Both species laid smaller clutches in the urban site and had positive selection for larger clutch sizes which did not differ in strength for the great tits but did for blue tits, with weaker selection in the urban population. Our results suggest that food availability for nestlings may be constraining urban birds, and that the temporal cues females use to time breeding correctly, such as tree budburst and food availability, may be absent or reduced in urban areas due to lower caterpillar availability. These results have implications for our understanding of the adaptation of wild animals to city life.Significance statementUrbanisation is expanding rapidly and changing the environment many species live in. A key challenge is to understand how species adapt to the urban environment, why some species can adapt, why others cannot and what we can do to ensure that cities are ecologically sustainable and biodiversity rich. Here we show that the strength of natural selection for early breeding and larger clutch size is weaker in urban than non-urban blue tits, likely due to reduced and irregular availability of natural insect food in urban areas. This effect was not found in great tits. Thus, urbanisation can alter the selection pressures wild animals are exposed to, but this effect may differ between species, even when closely related. This has implications for our understanding of how species adapt to urban life.

Heterothermy as the Norm, Homeothermy as the Exception: Variable Torpor Patterns in the South American Marsupial Monito del Monte (Dromiciops gliroides).

Hibernation (i.e., multiday torpor) is considered an adaptive strategy of mammals to face seasonal environmental challenges such as food, cold, and/or water shortage. It has been considered functionally different from daily torpor, a physiological strategy to cope with unpredictable environments. However, recent studies have shown large variability in patterns of hibernation and daily torpor (“heterothermic responses”), especially in species from tropical and subtropical regions. The arboreal marsupial “monito del monte” (Dromiciops gliroides) is the last living representative of the order Microbiotheria and is known to express both short torpor episodes and also multiday torpor depending on environmental conditions. However, only limited laboratory experiments have documented these patterns in D. gliroides. Here, we combined laboratory and field experiments to characterize the heterothermic responses in this marsupial at extreme temperatures. We used intraperitoneal data loggers and simultaneous measurement of ambient and body temperatures (TA and TB, respectively) for analyzing variations in the thermal differential, in active and torpid animals. We also explored how this differential was affected by environmental variables (TA, natural photoperiod changes, food availability, and body mass changes), using mixed-effects generalized linear models. Our results suggest that: (1) individuals express short bouts of torpor, independently of TA and even during the reproductive period; (2) seasonal torpor also occurs in D. gliroides, with a maximum bout duration of 5 days and a mean defended TB of 3.6 ± 0.9°C (one individual controlled TB at 0.09°C, at sub-freezing TA); (3) the best model explaining torpor occurrence (Akaike information criteria weight = 0.59) discarded all predictor variables except for photoperiod and a photoperiod by food interaction. Altogether, these results confirm that this marsupial expresses a dynamic form of torpor that progresses from short torpor to hibernation as daylength shortens. These data add to a growing body of evidence characterizing tropical and sub-tropical heterothermy as a form of opportunistic torpor, expressed as daily or seasonal torpor depending on environmental conditions.

KEBIASAAN MAKANAN IKAN DI SITU GONGGONG, KABUPATEN PANDEGLANG, BANTEN

Gonggong Lake is one of the lentic waters, located at Cipicung village Cikedal District Pandeglang Banten. Gonggong Lake is used as a source of water for irrigation rice fields, O. tilapia culture, tofu production, oncom , social activity, and fishing. This causes made the availability of natural food and resulted in the change balance of ecosystems in the waters. Natural fish foods are the main factor needed in the process of growth, reproduction, and survival of fish. Fish food habits in nature are important to be studied as an effort to manage fishery resources. The study aimed to determine to identify fish food habits in Gonggong Lake. The study was conducted from July to August 2017 at 4 stations, i.e. 1) inlet I; 2) inlet II; 3) center of the lake, and 4) outlet. Fish and food habits identification was conducted at the laboratory of aquaculture, University of Sultan Ageng Tirtayasa. The results of this study in Gonggong Lake, there are 5 species of fish caught namely Oreochromis niloticus , Barbonymus gonionotus , Trichogaster trichopterus , Channa striata , and Glossogobius giuris . Food habits in Gonggong Lake are dominated by herbivorous fish with main food of phytoplankton and plant parts. Natural foods are dominated by phytoplankton consist of the Chlorophyta, Chrysophyta, Cyanophyta, Cryptophyta, and Euglenophyta groups.

Nutrients and anti-nutrients in leaf litter of four selected mangrove species from the Sundarbans, Bangladesh and their effect on shrimp (Penaeus monodon, Fabricius, 1798) post larvae

The release of nutrients and anti-nutrients from mangrove leaf litter plays an important role in the biogeochemical cycling in aquatic environments and directly or indirectly affects water quality and food availability to shrimp. In this study, we assessed nutrient and anti-nutrient loss during decomposition of leaf litter at a concentration of 1 g/L for four mangrove species (Avicennia officinalis, Heritiera fomes, Sonneratia apetala, Sonneratia caseolaris) to monitor water quality and to estimate how leaf litter influences shrimp post larvae (PL) growth and survival. There were significant differences (P < 0.05) between the studied species in terms of mass loss of the leaf litter during the investigation period. There were also significant differences (P < 0.05) between the studied species in terms of loss of nutrients and anti-nutrients in the shrimp PL rearing tank during the four-week experimental period. Decomposing mangrove leaves stimulated availability of natural food for shrimp PLs. There was a strong positive correlation between mass loss and PL production. At the concentrations of leaf litter used, the anti-nutritional factors did not affect the PLs. PL survival with mangrove leaf litter was 75–82%, whereas all the PL died without any leaf litter. PL weight gain ranged from 0.83–3.33 mg/d where S. apetala leaf litter resulted in the highest PL growth rate, followed by A. officinalis, S. caseolaris and H. fomes, in that order (P < 0.05). Overall, mangrove leaf litter had a positive effect on shrimp performance in terms of growth and survival and this effect was highest for S. apetala leaf litter.

Studies on Primate Crop Feeding in Asian Regions: A Review

We reviewed previous literature on primate crop feeding in Asia. We found 134 reports from 14 different countries and regions. More than half of the crop feeding cases involved macaques, followed by colobines, especially common langurs, and to a lesser extent by orangutans. No crop feeding by gibbons, lorises, or tarsiers has been reported. Most reports obtained information about crop feeding through interviews with locals and recorded the crops damaged and troop composition, while a few recorded the activity of the target primates and their population parameters. Crop feeding increased when the field was located near the forest, and when natural food availability decreased. Most farmers used non-lethal countermeasures, while some farmers killed the monkeys, and a few used electrical fences to protect crops. In study sites inhabited by multiple animal species, primates are often the worst crop feeders. Human perception and attitudes toward crop feeding primates were affected by income, residential area, religion, and history of crop feeding. Recent studies have created models based on previous data to clarify the potential risk of crop feeding and to predict the monkeys' ranging patterns. To create models for reducing crop damage and to design conservation strategies, collecting fundamental information is necessary.

Feeding habits of Tinfoil barb, Barbonymus schwenenfeldii in the Tasik River, South Labuhanbatu, North Sumatra, Indonesia

Abstract. Desrita, Hasugian FK, Yusni E, Manurung VR, Rambey R. 2021. Feeding habits of Tinfoil barb Barbonymus schwenenfeldii in the Tasik River, South Labuhanbatu, North Sumatra, Indonesia. Biodiversitas 22: 2131-2135. Research on feeding habits of Tinfoil barb, Barbonymus schwanenfeldii was carried out in the Tasik River from July to August 2020. This study aims to determine the composition of foods consumed by Tinfoil barb fish, and the availability of natural food in the Tasik River from 3 sampling stations. Fishes were caught using a gillnet with a mesh size of 3.18 cm, then the fish samples were dissected, and the digestive tract was taken and preserved with 10% formalin. A total of 138 Tinfoil bars were caught for this study. Analysis of stomach contents found that Tinfoil barb ate phytoplankton (41-48%) as the primary food, moss (25-38%), plant pieces (13-17%), worms (2-11%) as a complementary food and few of insects (0-4%), zooplankton (0-1%) as other foods. Based on analysis of food item values, all types of food and ratio within the intestine length and the total length showed that Tinfoil Barb was classified as omnivorous. The availability of natural foods for Tinfoil Barb in the Tasik River consists of the genera Asteroinella, Bacillaria, Bidulphia, Cestom, Gyrosigma, Gonatozygon, Oscillatoria, and Thalassiora.

Post-larval Colossoma macropomum (Characiformes, Serrasalmidae) show better performance in excavated than concrete tanks under different feeding strategies

As the global human population increases, the demand for food grows and, consequently, practices such as aquaculture have become more common. Colossoma macropomum (Cuvier, 1818) is a native Amazonian species, considered to be the second most cultivated fish in the country. We compared the development of post-larval C. macropomum of different ages, submitted to combinations of food management on a commercial production scale. Two experiments tested the delivery of i) 55% crude protein feeding, ii) natural feeding by fertilizing the water and iii) a combination of both during hatchery in concrete tanks (10 m 2) or excavated soil-bottom tanks (4502) subjected to distinct fertilization protocols and storage densities. The weight and length of the post-larvae grown in ponds were greater (p &lt; 2.0x10-16) for the mixed treatment, except during the first week of larvae, in which values were similar (p ≤ 1.76x10-14) to the fertilization treatment. Concrete tanks with fertilization management without feeding were similar to the mixed treatment (p ≤ 1.38x10-7); however, during the first week of external larvae production, the growth performance under fertilization treatment was superior to the others. Food management in excavated tanks, when compared to the same management performed in concrete tanks, registered higher averages for the productive variables of C. macropomum cultivated at the density of 200 post-larvae m-2 in all evaluated food strategies. It was verified that post-larvae of C. macropomum did not develop well in the first weeks of life when receiving only formulated diets. The increase in natural food availability through fertilization positively influenced the performance of the species, which can remain without feeding until the second week of life.

Urban living influences the nesting success of Darwin's finches in the Galápagos Islands.

Urbanization is expanding worldwide with major consequences for organisms. Anthropogenic factors can reduce the fitness of animals but may have benefits, such as consistent human food availability. Understanding anthropogenic trade‐offs is critical in environments with variable levels of natural food availability, such as the Galápagos Islands, an area of rapid urbanization. For example, during dry years, the reproductive success of bird species, such as Darwin's finches, is low because reduced precipitation impacts food availability. Urban areas provide supplemental human food to finches, which could improve their reproductive success during years with low natural food availability. However, urban finches might face trade‐offs, such as the incorporation of anthropogenic debris (e.g., string, plastic) into their nests, which may increase mortality. In our study, we determined the effect of urbanization on the nesting success of small ground finches (Geospiza fuliginosa; a species of Darwin's finch) during a dry year on San Cristóbal Island. We quantified nest building, egg laying and hatching, and fledging in an urban and nonurban area and characterized the anthropogenic debris in nests. We also documented mortalities including nest trash‐related deaths and whether anthropogenic materials directly led to entanglement‐ or ingestion‐related nest mortalities. Overall, urban finches built more nests, laid more eggs, and produced more fledglings than nonurban finches. However, every nest in the urban area contained anthropogenic material, which resulted in 18% nestling mortality while nonurban nests had no anthropogenic debris. Our study showed that urban living has trade‐offs: urban birds have overall higher nesting success during a dry year than nonurban birds, but urban birds can suffer mortality from anthropogenic‐related nest‐materials. These results suggest that despite potential costs, finches benefit overall from urban living and urbanization may buffer the effects of limited resource availability in the Galápagos Islands.

Urban gulls adapt foraging schedule to human‐activity patterns

Numerous animals are able to adapt to temporal patterns in natural food availability, but whether species living in relatively novel environments such as cities can adapt to anthropogenic activity cycles is less well understood. We aimed to assess the extent to which urban gulls have adapted their foraging schedule to anthropogenic food source fluctuations related to human activity by combining field observations at three distinct urban feeding grounds (park, school and waste centre) with global positioning system (GPS) tracking data of gulls visiting similar types of feeding grounds throughout the same city. We found that the birds’ foraging patterns closely matched the timing of school breaks and the opening and closing times of the waste centre, but gull activity in the park appeared to correspond to the availability of natural food sources. Overall, this suggests that gulls may have the behavioural flexibility to adapt their foraging behaviour to human time schedules when beneficial and that this trait could potentially enable them to thrive in cities.

Seasonality, local resources and environmental factors influence patterns of brown bear damages: implications for management

AbstractCoexistence of humans and large carnivores is a major challenge for conservation and management, especially in human‐modified landscapes. Ongoing recovery of some large carnivore populations is good conservation news, but it also brings about increased levels of conflict with humans. Compensation payments and preventive measures are used worldwide as part of conservation programmes with the aim of reducing such conflicts and improving public attitude towards large carnivores. However, understanding the drivers triggering conflicts is a conservation priority, which helps prevent and reduce damages. Here, we have analysed the spatio‐temporal patterns of brown bear Ursus arctos damages to apiaries, crops and livestock in the two small, isolated and endangered bear populations in northern Spain. The increase in the number of damages varied in parallel with the increase in bear numbers, which is probably a primary cause determining the occurrence on damages. Damages also varied among years, seasons and bear populations and seemed to mainly depend on the local availability of natural food items, weather conditions and the availability of apiaries and livestock. Fluctuating availability of food items may explain the frequency of conflicts, which is yet another call to apply preventive measures in carnivore damage to human property in seasons and years when natural food availability is lower than usual. Understanding and preventing damage is in turn essential to mitigate conflicts where humans and large carnivores share the same landscape.

Using GPS and accelerometry data to study the diet of a top avian scavenger

ABSTRACT Capsule The Eurasian Griffon Vulture Gyps fulvus is an obligate scavenger relying on spatially and temporally unpredictable food resources. We demonstrate how high-frequency telemetry data can be efficiently used to identify vultures’ feeding locations in the wild and study their diet. Aims To study the Griffon Vulture diet composition, seasonal variations, and bathing frequency in an area with high natural food availability. Methods We used a remote-sensing technique based on GPS and accelerometry data to identify the feeding locations, and ground-truthing to identify the carcass species and investigate the causes of mortality. Results We identified 13 taxa in the diet of Griffon Vultures. Cattle comprised 48.5% of the diet, followed by sheep (24.3%), while wild animals were 13.1%. We observed seasonal variation in the proportion of small stock and game species in the diet. Predation was reported as the main cause of mortality (60.2%) for prey species, while natural causes accounted for 37.6%. Vultures were mainly feeding in areas south of their breeding colonies in Bulgaria and Greece. Natural springs and fountains were regularly used by the Griffon Vultures for bathing and drinking, especially in the summer. Conclusions Free-ranging livestock creates favourable feeding conditions for vultures, especially in areas with rugged terrain and a high density of predators. An increase in the number of wild ungulates can potentially buffer the fluctuations in livestock numbers and be beneficial for vultures, especially in the autumn and winter months. Lead ammunition must be substituted with non-toxic alternatives to reduce the exposure of vultures and other scavengers to lead poisoning.

Population expansion and breeding success of Bearded VulturesGypaetus barbatusin the French Pyrenees: results from long‐term population monitoring

Based on monitoring of Bearded Vultures over 24 years in the French Pyrenees, we assessed factors explaining temporal and spatial variations in numbers and breeding performance. The number of territorial pairs increased throughout the study period from 16 in 1994 to 44 in 2017. No significant negative trends in mean productivity (fledglings per territorial pair) were detected with increasing population size. Colonization probability increased significantly with breeding population size the previous year and with the regular provision of supplementary food in the territory the winter when colonization occurred. Colonization of new territories simultaneously increased the distribution range and local densities, but we found no effect of number of near neighbours on productivity. Pairs having bred less than 5 years together had a much lower probability of laying clutches, and higher lay rates were observed inside or close to protected areas after accounting for pair‐bond length, so productivity of territories inside protected areas was significantly higher. Nest success decreased with advanced lay date and increased with winter food abundance. Nesting failures in the study area were frequently associated with harsh weather. Additionally, disturbance by human activities was the second most important identified cause of breeding failure. The probability of failing due to disturbance was higher in western areas (where breeding areas are more accessible to humans), outside protected areas, and has increased with time. After a failure due to disturbance, there was a significantly higher probability of not producing a clutch the following year as compared with pairs that had not failed or had failed due to other causes, indicating deferred effects of disturbance. Our results show the benefits of conservation management actions, such as implementation of protected areas or designed supplementary food programmes in winter, to help range expansion. On the other hand, we did not find a significant effect of winter supplementary food on productivity. Management of feeding sites should be adapted to more specific planning, being used only in areas where natural food availability is scarce, avoiding its use close to breeding sites when juveniles disperse, and targeted mainly to help range expansion. Our results also highlight the importance of maintaining or enhancing good populations of wild ungulates and regulating human activities around nesting sites of this threatened species.

Suitability analysis of aquaculture ponds based on primary productivity parameters in mangrove area of Banda Aceh

Determining the suitability of aquaculture ponds is one of a valuable factor in sustainable aquaculture. One of the factors to consider in establishing a successful aquaculture is aquatic environment, i.e.: the primary productivity of waters and physical-chemical factors. The value of primary productivity describes aquatic trophic and natural food availability. This research was aimed to observe the suitability of aquaculture ponds based on primary productivity, phytoplankton abundance, and water quality (Physical-Chemical factors). The research was conducted on July to August 2018 in mangrove ecosystem at western and eastern coastal area of Banda Aceh with six observation stations, namely Beureunut, Amat Aramanyang, Ruyung, Tibang, Deah Glumpang and Peukan Bada. These stations were determined by stratified random sampling method based on water characteristic. The measurement of primary productivity was conducted by using the dark-light bottle method. The categorizing of suitability of aquaculture ponds was done by using the scoring method. The water quality parameters were given the value and score then following to be divided into four classes of suitability comprise Class S1 (Very suitable), S2 (Suitable), S3 (Conditional Suitable), and TS (Unsuitable). The results showed that the value of primary productivity ranged from 34.72 to 178.82 mgC/m3/hour and the phytoplankton abundance around 1.17 – 3.02 individual/Liter. Land suitability scoring ranged from 70.1 – 75.6%. It was concluded that the station 4th (Tibang) and 5th (Deah Glumpang) were a suitable area for aquaculture ponds with a score of 75.6%.

Individual and population fitness consequences associated with large carnivore use of residential development

AbstractLarge carnivores are negotiating increasingly developed landscapes, but little is known about how such behavioral plasticity influences their demographic rates and population trends. Some investigators have suggested that the ability of carnivores to behaviorally adapt to human development will enable their persistence, and yet, others have suggested that such landscapes are likely to serve as population sinks or ecological traps. To understand how plasticity in black bear (Ursus americanus) use of residential development influences their population dynamics, we conducted a 6‐yr study near Durango, Colorado, USA. Using space‐use data on individual bears, we examined the influence of use of residential development on annual measures of bear body fat, cub productivity, cub survival, and adult female survival, after accounting for variation in natural food availability and individual attributes (e.g., age). We then used our field‐based vital rate estimates to parameterize a matrix model that simulated asymptotic population growth for bears using residential development to different degrees. We found that bear use of residential development was highly variable within and across years, with bears increasing their foraging within development when natural foods were scarce. Increased bear use of development was associated with increased body fat and cub productivity, but reduced cub and adult survival. When these effects were simultaneously incorporated into a matrix model, we found that the population was projected to decline as bear use of development increased, given that the costs of reduced survival outweighed the benefits of enhanced productivity. Our results provide a mechanistic understanding of how black bear use of residential development exerts opposing effects on different bear fitness traits and a negative effect on population growth, with the magnitude of those effects mediated by variation in environmental conditions. They also highlight the importance of monitoring bear population dynamics, particularly as shifts in bear behavior are likely to drive increases in human–bear conflicts and the perception of growing bear populations. Finally, our work emphasizes the need to consider the demographic viability of large carnivore populations when promoting the coexistence of people and carnivores on shared landscapes.

KELIMPAHAN DAN DISTRIBUSI LARVA IKAN DI PERAIRAN PESISIR LAMPUNG TIMUR

Information abundance and distribution of fish larvae in coastal waters of East Lampung currently very limited. The research aimed to improve the knowledge of the early life of organisms, in order to manag biodiversity and biological resources in the waters. Research station representing the several water sectors: in-shore, near-shore, and off-shore. The research was a representation of eastern monsoon (June) and transition monsoon (September) in 2017. Fish larvae was harvested using bon ggo-net tool while its identification to family level using portable Dino-lite . Based on the result the Abundance of fish larvae in eastern monsoon was higher than transition monsoon. This research found 81 families of fish larvae. There were 10 dominant families, that are Gobiidae, Pegasidae, Mullidae, Pomacentridae, Sillaginiidae, Bleniidae, Bythitidae, Carangidae, Pseudochromidae and Bothidae. The distribution of fish larvae in the lower in-shore was higher than near-shore and off-shore, while east and transitional seasons have not much different larval catches. Temperature, salinity and pH parameters indicated optimal range state for survival and growth of fish larvae, brightness and turbidity in accordance with water quality standards, currents velocity on eastern monsoon is very fast while transition monsoon is fast to very fast. Phytoplankton and zooplankton showed sufficient natural food availability for the life of fish larvae. Result Canonnical Corespondence Analysis (CCA) analysis to connectivity of abundance and larvae distribution showed that the brightness parameter forming a point projection while other water environment condition parameters form a vector projection in both period of monsoon. The abundance and fish larvae distribution in coastal waters of East Lampung in all three sectors of the waters had proportionality to the parameters of environmental conditions, especially the current parameters and the difference of the monsoon period.

The Composition, Size Distribution and Growth Patterns of Penaeus monodon and Penaeus merguiensis at the Estuary of Tukad Aya, Jembrana Bali

Estuary ecosystem has an important role in supporting the life of shrimp. High productivity and the availability of natural food in the estuary ecosystem, will indirectly affect the growth of shrimp. Penaeus monodon and Penaeus merguiensis were two species of shrimp that had economic value with high demand. The purpose of this study was to determine the biological aspects of Penaeus monodon and Penaeus merguiensis shrimp at estuary of Tukad Aya, Bali. Data collection was carried out in February-March 2019 using quantitative descriptive research methods. The determination of the research station was done by purposive sampling. The results showed the total number of shrimps were caught 1,756 individuals, which consist of Penaeus monodon 151 individuals, Penaeus merguiensis 224 individuals and 1,325 individuals of other shrimp. The composition of Penaeus monodon (8.6%) was less than Penaeus merguiensis (12.76%). Shrimp length measurements were divided into 9 groups with a range of values of 55.15-189.95 mm in Penaeus monodon and 31.3-140.1 mm in Penaeus merguiensis. The results of the length and the weight regression in both species of shrimp obtained the value of b &lt;3 so that the growth pattern of shrimp was categorized as negative allometric where length growth was faster than weight gain.

Spatial ecology of non-breeding Eurasian Griffon Vultures Gyps fulvus in relation to natural and artificial food availability

ABSTRACT Capsule: The movements and spatial ecology of non-breeding Eurasian Griffon Vultures Gyps fulvus in northern Italy, Croatia and Austria do not seem to be affected by feeding station use. Aims: The purpose of this study was to assess how the creation of a feeding station at the Riserva Naturale Regionale del Lago di Cornino (Forgaria nel Friuli, northeast Italy) during the 1980s might have affected the spatial and behavioural ecology of the Eurasian Griffon Vulture. Methods: Using global positioning system (GPS) satellite tracking, we studied movements of nine non-breeding Eurasian Griffon Vultures within the Riserva Naturale Regionale del Lago di Cornino in Italy, the Hohe Tauern in Austria and the Kvarner Gulf in Croatia. Results: Both the average foraging range size and the time spent by the birds in Italy were comparable to those recorded in Croatia and Austria, where the vultures depend on unpredictable food resources. A significant difference in terms of foraging range size was recorded among seasons. In winter it seems to be smaller as a consequence of reduced movements performed by the individuals due to harsh climate conditions. Conclusions: Our results suggest that the creation of a feeding station in Forgaria does not seem to have affected the spatial ecology of the Eurasian Griffon Vulture. However, due to the limited sample size and the young age of the individuals monitored, which have a long dispersal period, the findings presented should be considered as preliminary. Further research needs to be implemented to inform decisions regarding the management of supplementary feeding stations to promote the recovery and conservation of scavenger species, particularly in areas in which they have declined massively.