Area Monitoring Program Research Articles

Comparison of fish assemblages recorded by visual census and video census

Introduction: Underwater visual censuses are the basis of many studies on fish ecology, however, a series of limitations and errors influence the traditional visual estimation of fish richness and abundance. Video techniques have been proposed to mitigate such errors, but there are few studies that compare the effectiveness of both methods. Objective: To compare the estimates obtained through the traditional census and the video census of the fish community of two localities in the central Mexican Pacific. Methods: We studied the fish community of two bays of Huatulco, Oaxaca, Mexico. We established sampling points in each bay and applied a traditional census and a diver-operated video census. We used comparison tests and analysis of similarity tests to compare richness, abundance and diversity by locality; and permutation tests for the same parameters at each sampling point. Results: Both censuses provide similar estimates regarding the richness, abundance, and diversity by locality and by sampling points. There were no statistically significant differences between traditional census and a diver-operated video census in terms of richness, abundance, and diversity. Conclusions: Video census using the diver-operated video technique can be used as a complement or as an alternative to traditional census. Its use can provide a more complete assessment, increase data acquisition, and implement long-term monitoring programs in areas where there are economic limitations for its operation.

Wolf-dog admixture highlights the need for methodological standards and multidisciplinary cooperation for effective governance of wild x domestic hybrids

Hybridisation between wild and domestic taxa raises complex questions for conservation. Genetic advances offer new methods for hybrid identification, yet social and cultural factors can influence study design, and the interpretation, application, and communication of results. A relevant illustration is hybridisation between domestic dogs (Canis lupus familiaris) and wild canids, such as grey wolves (C. lupus). For regional European monitoring programs in areas with expanding wolf populations, priorities include shared genetic markers and inclusion of all relevant reference populations to ensure dispersing wolves are identified as such and not classified as wolf-dog hybrids, which may cause harmful management decisions. Beyond technical developments, hybrid research and conservation management can benefit from improved integration of legal and policy perspectives, recognition of phenotypic traits as broadly unreliable for identification, and attention to the drivers of, and responses to, evolution in human-dominated landscapes. Additionally, the proliferation of unsubstantiated reports about hybrids in popular and social media shows that communication based on verified findings of hybridisation is essential. Hybridisation requires more constructive discussion on how to balance potentially competing conservation objectives, and the integration of multidisciplinary perspectives. These encompass the welfare of individual animals and preservation of historical predator-prey relationships. Conservation measures centred on preserving the ecological function of wild canids likely offer the most sustainable prospects but require improved understanding of the extent to which their behavioural ecology might differ from that of hybrids. Accurate genetic identification is required to fill this critical knowledge gap, advance public discourse, and initiate relevant conservation actions.

Impoundment, environmental variables and temporal scale predict zooplankton beta diversity patterns in an Amazonian river basin

The implementation of environmental monitoring programs in areas under anthropogenic pressure is essential to investigate the processes that generate and maintain biodiversity in ecosystems and to establish the most appropriate conservation strategies according to the area. We investigated whether environmental variables or temporal scale influenced zooplankton spatial diversity and beta diversity components in the Madeira River basin (Amazon tributary, Rondônia state, Brazil) from 2009 to 2015. We also investigated the local site contribution to overall beta diversity (LCBD) and to each of its components, to be able to propose conservation strategies more suitable for the river basin. Alpha diversity values decreased over time, while total beta diversity and the abundance difference component increased. A pattern of abundance difference (Podani family) dominated spatial beta diversity within the major sampling campaigns (at each time point). Environmental variables and heterogeneity, temporal scale (sampling campaigns), and also the dam installation contributed to variation in spatial beta diversity and its components. On the other hand, the flood pulse did not influence spatial beta diversity over time. Few sites contributed significantly to beta diversity prior dam installation, but most sites contributed significantly to beta diversity values at least at one point in time, in the post-dam phase. Thus, post-damming, all sites should continue to be monitored for conservation and restoration of zooplankton communities and biodiversity preservation, as changes are likely to still occur. Analysis of beta diversity, its components, and LCBD, are useful and efficient methods to study spatio-temporal changes in communities and identify critical sites. Impoundment and environmental variation significantly affect zooplankton community beta diversity, dependent on underlying mechanisms such as substitution or abundance differences that diversify communities spatially and temporally.

Palmageddon: the wasting of ornamental palms by invasive palm weevils, Rhynchophorus spp.

Urban areas landscaped with ornamental palms, especially Canary Islands date palms (Phoenix canariensis), are particularly vulnerable to incursion by invasive palm weevils, Rhynchophorus spp. (Coleoptera: Curculionidae). Metropolitan palmscapes are often resource rich in terms of palm species diversity and density, and these areas typically have numerous conduits (e.g., air, road, or sea transportation hubs) that assist with international and regional trade and tourism which can facilitate accidental or deliberate weevil introductions. Once established in urban areas, Rhynchophorus populations may be hard to suppress, from where they can expand their range and threaten agricultural commodities or native palms in wilderness areas. Here, we review current knowledge about relationships between Rhynchophorus invasions and urban environments. Further research areas should be addressed to improve forecasts of invasion risks and to complement management options for detection and control. We propose that greater attention be paid to quarantine restrictions on live palm movements and pro-active early detection and monitoring programs in areas deemed to be at high risk of invasion and establishment. In response to an incursion, we advocate the deployment of containment and eradication campaigns in urban zones when populations are small and highly localized.

Assessing environmental health using ecological indices for soft bottom in sewage-affected rocky shores: The case of the largest seaside resort of SW Atlantic

Efficient ecological indices can reflect the differences between impacted and nonimpacted sites, leading to significant variations at the contamination spatial scale. Here, we evaluated the spatial-temporal variability of 3 ecological indices (AMBI, M-AMBI, and BENTIX) in response to the distinct levels of sewage contamination. The indices were evaluated in two different ways: including Brachidontes rodriguezii (IBR) and excluding B. rodriguezii (EBR). The fact that mussel beds create a secondary infaunal habitat allows us to test these indices for soft bottoms in areas with rocky bottoms. The effectiveness and the level of agreement of these indices were increased when they were calculated with EBR. BENTIX and M-AMBI produced under- and overestimations of the ecological status of the studied sites. AMBI (EBR) seems to be better suited for environmental quality assessment in the study area. This index reduces the processing time of samples; thus, the AMBI (EBR) index could be used as a robust management tool for monitoring programs in areas with hard substrate.

Ecotoxicological Tools for Landfarming Soil Evaluation in a Petrochemical Complex Area

The demand for simple and rapid bioassays in ecotoxicological evaluations is of paramount importance in order to speed up environmental monitoring programs. In this study we performed bioassays with lettuce seeds and two species of terrestrial isopods (Armadillidium vulgare and Porcellio dilatatus) for the ecotoxicological assessment of a landfarming soil from a petrochemical complex area. The solubilized content of test soil demonstrated a concentration-response type toxic effect on seed germination rate, and a delay on germination, but showed toxic effect on seedlings wet weight only at the highest concentration. Toxic effects were also observed in mortality rate and avoidance behavior of the two woodlice species. These results demonstrated the sensitiveness of the organisms studied, and highlighted the possibility to use these bioassays in environmental monitoring programs in areas contaminated with fossil fuels.