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Lake Taal is one of the most significant lake ecosystems in tropical East Asia. In 2011, a review paper consolidated all known biodiversity and limno-ecological studies conducted in Lake Taal from the beginning of the 20th century all the way to the late 2000s. It highlighted that insufficient funding, inadequate long-term monitoring data, and the publication culture of that time impeded having a comprehensive understanding of the lake. Since then, much research work has been done in Lake Taal, especially during the past decade. This review paper provides an analysis and summary of the research work conducted in Lake Taal over the past 10 years. The recent decade has seen a steady increase in scientific interest in Lake Taal made evident by more scientists and institutions working on topics involving the lake. Research grants, collaborations, and publications have also significantly increased during the past 10 years. This has led to an improved understanding of the lake's biodiversity, ecology, and impacts of intensive aquaculture and the introduction of non-native species. Taken together, this paper presents a better understanding of Lake Taal, which can be utilized for the design and improvement of conservation, preservation, and management programs for this multi-use freshwater system. [ABSTRACT FROM AUTHOR]

One hundred eighty-three individuals of Glossogobius aureus, native to Lake Taal, Philippines, were collected in 2021–2022. Of these, 4 endohelminths were found and identified: Andracantha gravida (Acanthocephala: Polymorphidae), Schyzocotyle acheilognathi (Platyhelminthes: Bothriocephalidae), Azygia sp. (Platyhelminthes: Azygiidae), and Opegaster minima (Platyhelminthes: Opecoelidae). These helminths represent new host records for G. aureus and provide novel contributions to the recent Philippine parasite biodiversity listing. Among these 4 helminths, Azygia sp. was the most prevalent, had the highest percent dominance and mean intensity, and had a broader range followed by S. acheilognathi, A. gravida, and O. minima, respectively. These findings highlight the need to further explore Lake Taal's parasitofauna, especially with regard to the invasion of S. acheilognathi, and the transmission specificity of O. minima, which can be utilized as a keystone parasite biomarker and in return aid in the management and conservation efforts in Lake Taal. [ABSTRACT FROM AUTHOR]

In developing countries such as the Philippines, the inadequacy of even the most basic limnological datasets available has hindered planning and implementation of science-based management policies for inland waters. This situation is aggravated by overutilization of natural resources for ecosystem services such as water usage, aquaculture, fishing, and tourism. We reviewed published researches related to the Seven Maar Lakes (SMLs) in Luzon Is., Philippines to summarize information invaluable for the protection and sustainable use of these resources. Popular scientific search engines were utilized to gather peer-reviewed research articles and reports from both private institutions and government agencies. Literature and timeline from the 1930s to 2019 was classified into topics – namely socioeconomics, fisheries, biodiversity, and environment. Based on the literature survey, a variety of challenges, knowledge gaps, and promising research directions were identified, which are essential to the sustainable ecosystem management of the SMLs. Aquaculture practices impacting the lakes and its underestimated biodiversity were described. Measured vertical profiles of dissolved oxygen (DO), temperature, conductivity, pH, and salinity was supplemented by our preliminary limnological survey in the SMLs. Past and present monitoring data of selected physicochemical parameters were assessed from which the changing limnological status of the lakes was determined. We recommended measures motivated by strategic environmental assessments while still considering maintained economic yields. A sustained collaborative effort from different sectors is strongly suggested not only to manage the SMLs but also to address trade-offs among critical ecosystem services. Aside from the need for well-designed, long-term water quality monitoring, we also stress the synergistic interpretation of all available knowledge, which can contribute to the resolution of environmental issues at both local and global scales. [ABSTRACT FROM AUTHOR]

In this paper, we aimed to contribute to the conservation research of a heavily impacted tropical lake ecosystem by characterizing its previously undescribed fish diversity and also elucidating the trophic structure of its fish community. Our study area is Lake Sampaloc, a small crater lake in the southern region of Luzon Island, Philippines. This lake has been heavily used for economic resource functions, such as aquaculture, for decades. Hindrances to the effective implementation of regulatory provisions have produced detrimental ecological effects on the lake, which has recently been declared as "Threatened Lake of the Year 2014". We employed several sporadic fish surveys during a span of two years (2012 to 2014) to identify fishes in the lake. We also used stable isotope analysis to elucidate the trophic level and production reliance of important aquatic consumers. We discovered that the lake fish populations are heavily reliant on periphyton production and are mostly composed of non-native and potentially established invasive fish species. In addition, trophic niche overlaps are observed among non-native fish and native species. For the past three decades, Lake Sampaloc has been classified as eutrophic with high phytoplankton standing biomass. A possible direction for lake rehabilitation research is to investigate ways to change the present turbid state into a clear water system that is predominantly composed of submerged native vegetation. Such a macrophyte-based environment may help sustain the development and recruitment of native juvenile fish and also provide a more diverse functional habitat for fish assemblages that have overlapping trophic niches. [ABSTRACT FROM AUTHOR]

Macrophytes play an important role in the aquatic ecosystem since they are good bioindicators and serve as habitat for littoral fishes. This research involves the use of the hydroacoustic method aided by visual observation and quantification in determining the distribution and abundance of submerged macrophytes in the littoral zones of Lake Taal. The results were used to generate spatial distribution and percent cover maps of macrophytes in the lake. Based on the surveys, five macrophyte species were present in Lake Taal. Denser macrophyte beds were concentrated in the south basin of the lake. High nutrient levels in the south basin contributed to heavy macrophyte growth in this area, which usually come from run-offs from the residential, commercial and agricultural watersheds. The lesser biomass of macrophytes in the north basin was attributed to clearing activities due to the construction of fish cages for aquaculture. Furthermore, we were able to observe that there were different dominant species in the north and south basins of the lake; Najas indica was more prominent in the north basin, while Vallisneria nanawas more common in the south. This study shows that anthropogenic sources of excess nutrients and other activities such as aquaculture play a role in altering the distribution of macrophytes in Lake Taal and how these can have potential detrimental impacts to the littoral zones of the lake. [ABSTRACT FROM AUTHOR]