The Organoleptic Properties of Food Products from Tempe Lake Fish

The potential freshwater fish of Lake Tempe has long been consumed by the local community. However, its use is minimal. This article describes the organoleptic properties of fish cakes and fish floss as the development of various forms of food made from fish of Tempe Lake. The types of fish used as essential ingredients are Channa Striata and Monopterus Albus. The organoleptic test involved 70 panelists from the Department of Agricultural Technology, Universitas Negeri Makassar. Panelists assessed the color, taste, smell, and texture of the two food products. This result of the study describes the results of the organoleptic test with a comparison figure and t-test. Organoleptic test results showed that the panelists preferred the fish floss from Channa Striata for color, smell, and taste compared to fish floss from Monopterus Albus. Panelists' assessment of the fish cake from Channa Striata was better on smell and texture, while Monopterus Albus was preferred on the color and taste test. The T-test results showed that the panelists' assessments for fish cakes from Channa Striata and Monopterus Albus were similar. However, the organoleptic characteristics of fish cake are different between two kinds of lake fish.

Metal Contents of Lake Fish in Area Close to Disposal of Industrial Waste

This research was conducted to analyze the content of Fe, Cu, Cd, Cr, and Pb in several species of fish taken from three lakes that are close to the disposal of industrial waste in Indonesia. The fish samples were taken from three lakes, namely, Muara Angke, Weda, and Morowali. The samples from Morowali were analyzed in April 2019, those from Weda from November to December 2019, and those from Muara Angke in June 2018. All the samples were then analyzed at the Chemistry Laboratory of the Department of Chemistry, Faculty of Mathematics and Natural Science, University of Indonesia, and the Integrated Laboratory of IPB. The main results showed that all types of fish from Morowali and Weda were no longer safe to consume because they contained Fe, Cu, Cd, and Cr exceeding the threshold of metal contamination. Meanwhile, all types of fish from Muara Angke, except for ayam-ayam, are still safe for consumption. The results of this study can be a source of information regarding metal content in fish and fish feed for safe consumption. Given the high consumption rate of fish and the hazards of heavy metals on humans’ health, such research must be furthered.

Growth of Lahontan Cutthroat Trout from multiple sources re-introduced into Sagehen Creek, CA

Lahontan Cutthroat Trout Oncorhynchus clarkii henshawi have experienced massive declines in their native range and are now a threatened species under the US Endangered Species Act. A key management goal for this species is re-establishing extirpated populations using translocations and conservation hatcheries. In California USA, two broodstocks (Pilot Peak and Independence Lake) are available for translocation, in addition to potential wild sources. Yet suitability of these sources for re-introduction in different ecosystem types and regions remains an open and important topic. We conducted growth experiments using Lahontan Cutthroat Trout stocked into Sagehen Creek, CA USA. Experiments evaluated both available broodstocks and a smaller sample of wild fish translocated from a nearby creek. Fish from the Independence Lake source had significantly higher growth in weight and length compared to the other sources. Further, Independence Lake fish were the only stock that gained weight on average over the duration of the experiment. Our experiments suggest fish from the Independence Lake brood stock may be useful for re-introduction efforts into small montane headwater streams in California.

101 lakes - lentic fish community monitoring using eDNA metabarcoding

We have recently developed and deployed methods for environmental DNA (eDNA) based monitoring of lake fish communities in the UK. This approach combines eDNA with modern High-Throughput-Sequencing technology, so-called eDNA metabarcoding. This non-invasive method has proven to be more effective at detecting elusive species than established invasive surveying techniques such as electro fishing or fyke netting and can provide meaningful semi-quantitative abundance estimates. The UK Environment Agencies have funded the collection of an eDNA meta-barcoding data set of vertebrates from 101 UK lakes covering a broad spectrum of environmental conditions Fig. 1. This dataset is based on analysing 20 water samples per lake and has successfully been used to develop a WFD compatible water quality assessment tool. In its current form this tool is suitable for reporting the status of fish in water bodies where eutrophication is the dominant pressure. DNA is not homogeneously distributed in lentic environments and hence the detection of species relies on the collection of an adequate number of samples from a water body to capture the eDNA signal. Previous analyses on a subset of lakes have indicated that the number of samples used for the 101 lake fish data set is more than sufficient to reliably estimate species richness of lakes, but it is unclear how exactly reduced sampling effort affects other biodiversity estimates and inferences made about water quality. As the number of samples determines the cost of monitoring programmes it is essential that the sampling effort is optimised for a specific monitoring objective. The objective of this study was to explore the effect a reduced sampling effort would have on various biological inferences using algorithmic and statistical resampling techniques. with a much lower number of samples. For example, almost 90% of lakes achieved a sample coverage of 95% with only 10 samples. However, rare species are more often missed with fewer samples, with implications for monitoring programs of invasive or endangered species. Estimates of community composition and the ecological quality ratio (EQR) responded slowly to decreasing sampling effort. For example, subsets of 10 samples were in most cases much more closely related to each other than to sample sets from other lakes and showed very similar Ecological Quality Ratios. These results are able to inform the design of eDNA sampling strategies, so that these can be optimised to achieve specific monitoring goals.

Fossil fish species and assemblage are relevant integrative paleo-biogeo-archives in ancient lakes

<p>In paleontological context, fish remains are frequently collected and constitute a large part of the lake macro-fossil assemblages. In the presentation, examples from continental Africa chosen in lakes of different dimension, shape and history (mainly Malawi, Chad and Turkana) will illustrate how fish fossil study potentially provides a wide range of information on the paleoenvironment (water salinity, temperature, oxygenation, seasonality, etc.) and the paleogeography (watershed connections) of the lake and its basin. It is based on the knowledge of the ecology and phylogeny of the species and through dedicated biogeochemical and sclerochronological studies of their bones and teeth that also constitute paleo-bio-archives that recorded certain environmental information. Alongside the results extracted from each dedicated study, their combination provide new information and show the gain of extracting different and independent informations from the same object or from objects from the same assemblage, and notably in the case of lake-fish assemblages. For example, the combination of the knowledge on a fish paleo-ecology in a lake with results of a biogeochemical study of their remains can evidence change in the hydrographical regime between successive lake deposits. Finally, fish study also allow an interpolation of change in paleoenvironments at different time scales and their integrative study as paleoenvironmental proxy should be more widely included in the evolution of lakes in the past. The multi-time scale and proxy study enabled on fossil fish is sensible for transfer to predict modern lake evolution.</p>