Biology subjects

Pizarro, V.

Publications and source records attributed to Pizarro, V..

3 recordsLinked to original sources

bioRxiv2023

Spatial and temporal representation of marine fish occurrences available online

Despite the 243,000 species of marine species described by 2022, our knowledge about the biodiversity in the oceans is still incomplete. This may have dreaded and detrimental effect for the conservation of marine ecosystems under the current anthropization of our biota and the fast pacing climate and global change scenario. However, a large number of online repositories cataloging, storing and distributing biodiversity information hosting taxonomic information and species occurrence data have emerged recently. FishBase, the Global Biodiversity Information Facility (GBIF) and the Ocean Biodiversity Information System (OBIS) are part of these publicly available repositories representing a variety of sources that have exploded in number. However, despite the incredible accumulation of biodiversity records, not all the information is really useful, nor does it represent any new knowledge regarding global species richness patterns. In this study we evaluated the spatial and temporal representativeness of the records of marine fishes (order Actinopterygii) available in the GBIF and OBIS global repositories. We provide a methodological framework based on a set of non-parametric estimators to calculate species richness from incidence data, using hexagonal grids as sampling units overlapped on the marine bioregions worldwide. Using standard ecological and spatial analysis tools, we identify regions that are adequately represented in terms of available records and therefore have more reliable data, as well as regions with few records that do not represent current species richness. We overlap these results with the location of marine protected areas and fishing exploitation zones to understand the anthropogenic effect on marine ichthyofauna. We additionally evaluate hypotheses regarding the taxonomic, geographic, and temporal distribution of information biases to deepen our current understanding of public records of species occurrences worldwide. Considering that more than 40 years of information was analyzed, the results showed that on a global scale, the primary data on marine fish available on GBIF and OBIS platforms are still far from being representative and complete. Only 1.14% of the records were useful for our analyses. In addition, we found that the information seems to be biased towards coastal areas, regions close to developed countries and areas where there is a large fishing activity. Finally, the best represented species and families are those with a small body size, which use shallow habitats and have commercial cultural value.

ecology↗

bioRxiv2021

Physiological and ecological consequences of the water optical properties degradation on reef corals

Degradation of water optical properties due to anthropogenic disturbances is a common phenomenon in coastal waters globally. Although this condition is associated with multiple drivers that affect corals health in multiple ways, its effect on light availability and photosynthetic energy acquisition has been largely neglected. Here, we describe how declining the water optical quality in a coastal reef exposed to a turbid plume of water originating from a man-made channel compromise the functionality of the keystone coral species Orbicella faveolata. We found highly variable water optical conditions with significant effects on the light quantity and quality available for corals. Reduction of light penetration into the water column elicits the development of low-light phenotypes close to theoretical limits of photoacclimation despite their occurrence at shallow depths. Predicted photosynthetic energy depletion with increasing depth is associated with patterns of colony mortality and contraction of the habitable space for the population. A numerical model illustrates the potential effect the progressive degradation of water optical properties on the gradual mortality and population decline of O. faveolata. Our findings suggest that preserving the water optical properties seeking to maximize light penetration into the water column may have an extraordinary impact on coral reefs conservation, mostly toward the deeper portions of reefs.

physiology↗

bioRxiv2020

Coral reef restoration efforts in Latin American countries and territories

Coral reefs worldwide are degrading due to climate change, overfishing, pollution, coastal development, bleaching and diseases. In areas where natural recovery is negligible or protection through management interventions insufficient, active restoration becomes critical. The Reef Futures symposium in 2018 brought together over 400 reef restoration experts, businesses, and civil organizations, and galvanized them to save coral reefs through restoration or identify alternative solutions. The symposium highlighted that solutions and discoveries from long-term and ongoing coral reef restoration projects in Spanish-speaking countries in the Caribbean and Eastern Tropical Pacific were not well known internationally. Therefore, a meeting of scientists and practitioners working in these locations was held to compile the data on the extent of coral reef restoration efforts, advances and challenges. Here, we present unpublished data from 12 coral reef restoration case studies from five Latin American countries, describe their motivations and techniques used, and provide estimates on total annual project cost per unit area of reef intervened, spatial extent as well as project duration. We found that most projects used direct transplantation, the coral gardening method, micro-fragmentation or larval propagation, and aimed to optimize or scale-up restoration approaches (51%) or provide alternative, sustainable livelihood opportunities (15%) followed by promoting coral reef conservation stewardship and re-establishing a self-sustaining, functioning reef ecosystem (both 13%). Reasons for restoring coral reefs were mainly biotic and experimental (both 42%), followed by idealistic and pragmatic motivations (both 8%). The median annual total cost from all projects was $93,000 USD (range: $10,000 USD - $331,802 USD) (2018 dollars) and intervened a median spatial area of 1 ha (range: 0.06 ha - 8.39 ha). The median project duration was 3 years; however, projects have lasted up to 17 years. Project feasibility was high with a median of 0.7 (range: 0.5 - 0.8). This study closes the knowledge gap between academia and practitioners and overcomes the language barrier by providing the first comprehensive compilation of data from ongoing coral reef restoration efforts in Latin America.

ecology↗