Soil Acidification, Mineral Neoformation and Heavy Metal Contamination Driven by Weathering of Sulphide Wastes in a Ramsar Wetland

Past waste disposal practices have left large volumes of sulphidic material stockpiled in a Ramsar wetland site on the Atlantic coast of southwestern Spain, leading to severe land degradation. With the aim of addressing this legacy issue, soil core samples were collected along two transects extending from the abandoned stockpiles to the adjacent marshland and subjected to XRD, SEM-EDS, ICP-OES and ICP-MS analyses. Sulphide oxidation has been shown to be a major driver of acid generation and metal leaching into the environment. The marsh soil receiving acid discharges from the sulphide wastes contains elevated levels (in mg kg−1) of Pb (up to 9838), As (up to 1538), Zn (up to 1486), Cu (up to 705), Sb (up to 225) and Tl (up to 13), which are retained both in relatively insoluble secondary minerals (mainly metal sulphates and oxides) and in easily soluble hydrated salts that serve as a transitory pool of acidity and available metals. By using a number of enrichment calculation methods that relate the metal concentrations in soil and their baseline concentrations and regulatory thresholds, there is enough evidence to conclude that these pollutants may pose an unacceptable risk to human and ecological receptors.

Human impacts and Anthropocene environmental change at Lake Kutubu, a Ramsar wetland in Papua New Guinea

The impacts of human-induced environmental change that characterize the Anthropocene are not felt equally across the globe. In the tropics, the potential for the sudden collapse of ecosystems in response to multiple interacting pressures has been of increasing concern in ecological and conservation research. The tropical ecosystems of Papua New Guinea are areas of diverse rainforest flora and fauna, inhabited by human populations that are equally diverse, both culturally and linguistically. These people and the ecosystems they rely on are being put under increasing pressure from mineral resource extraction, population growth, land clearing, invasive species, and novel pollutants. This study details the last ∼90 y of impacts on ecosystem dynamics in one of the most biologically diverse, yet poorly understood, tropical wetland ecosystems of the region. The lake is listed as a Ramsar wetland of international importance, yet, since initial European contact in the 1930s and the opening of mineral resource extraction facilities in the 1990s, there has been a dramatic increase in deforestation and an influx of people to the area. Using multiproxy paleoenvironmental records from lake sediments, we show how these anthropogenic impacts have transformed Lake Kutubu. The recent collapse of algal communities represents an ecological tipping point that is likely to have ongoing repercussions for this important wetland’s ecosystems. We argue that the incorporation of an adequate historical perspective into models for wetland management and conservation is critical in understanding how to mitigate the impacts of ecological catastrophes such as biodiversity loss.

Analyses Implementation Realities of Legal Frameworks for Sustainable Management of Tanguar Haor Fisheries Resources in Bangladesh

Tanguar Haor (TH) is considered one of the Ecologically Critical Areas (ECAs) of Bangladesh and is internationally recognized as RAMSAR wetland (2nd Ramsar site) known to provide multiple ecosystem services to the society. Nevertheless, multidimensional threats and stressors, the capacity to supply ESs, and the biodiversity of the TH significantly degrades and threatens this wetland’s conservation and sustainability. Although the legal framework promises the sustainable conservation of fisheries resources, information on the implementation scenarios of fisheries laws, regulations, and policies in the TH Ramsar are scant. By merging qualitative and quantitative data of primary and secondary sources, this research aimed to analyze the legal framework to check the effectiveness of regulations for non-conflicting fisheries resources and the sustainable conservation of the TH Ramsar. Primary empirical data were collected by employing Participatory Rural Appraisal (PRA) tools, i.e., 204 semi-structured questionnaire-based individual interviews with fishers, three focus group discussions, and 14 key informants’ interviews in three fishing villages in the TH. In contrast, secondary data was set by reviewing published literature and related official documents. Results showed that, due to weak enforcement with inadequate surveillance and poor implementation of the legal framework, there was a high non-compliance with fishing laws, rules, and policies. Destructive and prohibited fishing gears, e.g., the use of small mesh fine nylon nets (current jal), purse seine net (ber jal), and the harvesting during ban period-illicit catch were widespread in the study areas. In addition, catching undersized fish, fishing at the restricted areas (sanctuary area), and fishing during spawning seasons occur often. There is a crying need for a comprehensive legal and policy framework to contextualize the local context, ensure the proper implementation of the fishing laws and regulations, increase the managerial inefficiency of enforcing agencies, ensure livelihood support during the fishing ban, and afford good alternative income options are still significant issues for good governance in the Tanguar Haor ECA. Findings might help to identify the gaps and misunderstanding of the existing legal practice while submitting urgent attention to the need for drawing a comprehensive legal and policy framework (contextually modified according to the local context), taking initiatives and acting synchronously for proper implementation, and calling transdisciplinary collaboration and cooperation among the agencies that may ensure the non-conflicting use of the natural resources of the TH that can be also helpful for the better conservation of this Ramsar wetland.