Faktor Hidro-Oseanografi Terhadap Distribusi Air Tawar Bersuhu Rendah Dekat Pantai Sekitar Lokasi Keluaran Air Tanah Lepas Pantai (KALP) di Perairan Lombok Utara, Indonesia

<p><strong>The Influence of Hydro-Oceanography Factors on the Distribution of Near-shore Low-Temperature Freshwater around Submarine Groundwater Discharge (SGD) Area in the North Lombok Waters, Indonesia.</strong> North Lombok coast has lot of resources of Submarine Groundwater Discharge (SGD). The biggest discharge appeared in the Krakas Beach where cold groundwater discharge many spots might trigger anomalies in the ambient water temperature. This study was aimed at determining the distribution of the cold groundwater discharge. A field survey was conducted on March 23th -26th, 2016. Flow model and statistical analysis were employed to determine the transport pattern of temperature anomalies. Vertically, the current direction is in accordance with Ekman spiral that triggers the vertical cold groundwater distribution. The current speed during the displacement toward high tide ranges 0-0.15 cm/s which predominantly moves south-westward. During low tide, tidal current was predominantly north-eastward moving at 0-0.3 cm/s. Temperature variation around the SGD spot fluctuated following sea surface surface elevation dynamics in which these two parameters has a correlation value of 63%.</p>

Effects of long-term elevated temperature on covering, sheltering and righting behaviors of the sea urchinStrongylocentrotus intermedius

Increases in ocean temperature due to climate change are predicted to change the behaviors of marine invertebrates. Altered behaviors of keystone ecosystem engineers such as echinoderms will have consequences for the fitness of individuals, which are expected to flow on to the local ecosystem. Relatively few studies have investigated the behavioral responses of echinoderms to long-term elevated temperature. We investigated the effects of exposure to long-term (∼31 weeks) elevated temperature (∼3 °C above the ambient water temperature) on covering, sheltering and righting behaviors of the sea urchinStrongylocentrotus intermedius. Long-term elevated temperature showed different effects on the three behaviors. It significantly decreased covering behavior, including both covering behavior reaction (time to first covering) and ability (number of covered sea urchins and number of shells used for covering). Conversely, exposure to long-term elevated temperature significantly increased sheltering behavior. Righting response inS. intermediuswas not significantly different between temperature treatments. The results provide new information into behavioral responses of echinoderms to ocean warming.

Effectiveness of Livewell Additives on Largemouth Bass Survival

Livewell conditions during competitive angling events are thought to affect fish mortality. We examined the effects of livewell additives on initial and delayed mortality of largemouth bass Micropterus salmoides. We applied three treatments (salt, ice, or salt and ice) to livewells during tournaments conducted on lakes in Illinois, United States, as well as in laboratory and pond experiments designed to examine the effects of fish size and ambient water temperature on mortality. Fish were collected after tournament weigh-in procedures were completed and monitored for delayed mortality every 24 h for 5 d. Initial mortality did not differ among livewell additives during these field experiments. Although delayed mortality was high (35%), it was not significantly different among livewells that contained salt (56%), ice (48%), ice and salt (40%), and controls (30%). Additives administered during the laboratory experiments, at cool water temperatures, resulted in significantly lower delayed mortalities than those observed during the field experiments when ambient water temperatures were warmer. Initial and delayed mortality did not differ among livewell additives during the laboratory experiments. Larger fish in field experiments had significantly greater delayed mortality than smaller fish in the pond experiments even though initial and delayed mortality did not differ among livewell additives. Our results suggest that fish size and ambient water temperature have a greater influence on delayed mortality observed during competitive angling events than the specific livewell additives studied here.

Seasonal diving patterns and body temperatures of juvenile green turtles at Heron Island, Australia

This study compared diving patterns of juvenile green turtles, Chelonia mydas, in a coral reef habitat during summer and winter. Dataloggers were deployed on green turtles at Heron Island, Australia, during December 2000 and August 2001 so that dive variables and ambient water temperature (TW) could be monitored. Cloacal temperatures (TB) were recorded from green turtles upon capture to assess their ability to maintain a thermal gradient between TB and TW. Data show that green turtles altered diving behaviour seasonally. Green turtles spent significantly more time in shallow water (<1 m) during winter than during summer. Dive depth for dives that exceeded 1 m was 2.9 ± 0.4 m (mean ± SEM) during summer and 4.4 ± 0.6 m during winter. Dive duration in summer (13.1 ± 1.2 min) was approximately half the dive duration in winter (24.3 ± 1.6 min), and surface interval in summer (0.6 ± 0.1 min) was one-third that of the surface interval in winter (1.8 ± 0.1 min). The observed changes in behaviour may be due to seasonal changes in environmental and physiological factors. There was no statistically significant difference between TB and TW during summer or winter.

Swimming behaviour and migration of a swordfish recorded by an archival tag

An archival tag equipped with sensors for temperature, depth and luminous intensity is an excellent method to elucidate behaviour and migration of marine organisms. Herein, what we believe is the first successful archival tag experiment with swordfish in the world is reported. The swordfish, which was harpooned with an archival tag encased in a plastic capsule, was released in July 1999 off the east coast of Japan. The fish was recaptured by a harpoon fishing vessel in June 2000, only 103 km from the tagging location and weighed approximately 120-kg. By comparing the water temperature data of the archival tag with oceanographic data, a cyclic seasonal migration between the food-rich Oyashio cold current area (40–45°N) during summer and the subtropical wintering area (10–20°N) was suggested. During most of the days of observation and for the majority of the time within a day, tagged fish swam in cold water (3–6°C) and deeper than approximately 200 m; at night, fish generally stayed near the warmer surface waters (21–27°C). The greatest swimming depth was approximated to be 900 m, deduced from ambient water temperature data. The swimming depth and behaviour pattern changed in response to the ambient water temperature.

Incorporation of strontium, cadmium, and barium in juvenile spot (Leiostomus xanthurus) scales reflects water chemistry

We investigated the hypothesis that strontium:calcium (Sr:Ca), cadmium:calcium (Cd:Ca), and barium:calcium (Ba:Ca) composition in scales reflects that of the ambient seawater in which fish were reared under controlled experimental conditions. Juvenile spot (Leiostomus xanthurus) were held in replicate tanks containing four different concentrations of Sr, Cd, and Ba maintained at either 20 or 25°C for a total of 42 days. The elemental composition of scales from these fish was analyzed at the termination of the experiment, using isotope dilution inductively coupled plasma mass spectrometry (ICP-MS). Sr, Cd, and Ba levels in the scales, expressed as ratios to Ca, were linearly related to environmental concentrations, indicating that the elements were incorporated in constant proportions to levels in the ambient water. Temperature had no measurable effect on the uptake of Sr, Cd, or Ba into the scales. Finally, Sr:Ca and Ba:Ca ratios in scales were highly correlated with levels in the otoliths from the same treatment. In all, Sr:Ca, Cd:Ca, and Ba:Ca signatures in scales appear to be representative of the ambient environment and, therefore, may be useful for quantifying life-history characteristics of individual fish.

Precise X-Ray Microfluorescence Measurements of Sr/Ca Ratios In Corals For Paleotemperature Analysis

Coral aragonite encodes a rich, complex record of ambient environmental conditions (including temperature, salinity, pollutants) during skeletogenesis. Annual growth banding in appropriate species provides an internal calendar, and the rapidity of skeletal growth permits temporal sampling to at least a sub-monthly basis. The longevity of reef coral colonies can provide continuous centuries-long environmental records. The presence of well-dated Pleistocene coral reefs at sites across the world ocean extends this record into the more distant past. Thus corals are a remarkable resource for the investigation of environmental conditions over perhaps 7 orders of magnitude of time.The past few years have seen considerable use of Sr/Ca ratios in scleractinian corals to reconstruct sea surface temperatures (SSTs) to document global change. The detailed correlation between Sr/Ca ratios in living corals and measured ambient water temperature is often remarkable, as is the match in older corals between Sr/Ca ratios and such other SST temperature proxies as 18O /16O ratios.