Biology subjects

Perez-Matus, A.

Publications and source records attributed to Perez-Matus, A..

4 recordsLinked to original sources

bioRxiv2025

Understory low compositional stability enhances functional stability in response to bull kelp removal in southern Chile

Background and Aims.Ecological stability is central to understand the ability of natural systems to respond to disturbances, especially when these occur directly over important species within communities, such as foundational species. The bull kelp Durvillaea incurvata is common in intertidal and shallow subtidal rocky shores, supporting a diverse understory. The direct harvesting of Durvillaea constitute a common practice along the Chilean coast able to disrupts the abundances of the understory community and as well aggregated properties such as overall community biomass. Thus, we investigated the resistance, resilience, and recovery of the understory community of Durvillaea subjected to an experimental kelp removal in two sites from the temperate Chilean coast. Methods.We simulated a pulse removal of Durvillaea cause by direct harvesting, by removing once all the individuals within experimental plots and then we monitored the composition and biomass of the sessile and mobile understory community for 25 months. Key Results.After the disturbance we observed a rapid recovery of Durvillaea cover and varying stability responses of the understory community. Community composition showed a low resistance to the disturbance but returned rapidly within 5 - 7 months to pre disturbance levels (high resilience), however showed an incomplete recovery compared to controls. While community biomass displayed high resistance to the disturbance and then remained constant across time (resilience = 0), showing a complete recovery compared to control communities. Conclusions.Differing from Durvillaea dominated communities from other regions, our analyzed communities showed rapid recovery dynamics in compositional and functional aspects, resulting highly resilient to the type of disturbance applied. In addition, since varying stability responses reported, we encourage the use of multiple dimensions of stability to exhaustively characterize the responses of Durvillaea dominated communities and other kelps, when exposed to disturbances.

ecology↗

bioRxiv2023

Rapid population recovery of a foundation species from experimental small-scale harvesting

Ecological stability is central to understand how disturbances challenge the persistence of populations and communities through time, particularly when species with strong effects on other species are disturbed. The bull kelp Durvillaea incurvata is a foundation habitat forming species that provides habitat, food, and shelter for various species, and supports the livelihoods of human communities along the southeast Pacific coast of Chile. Harvesting of D. incurvata has raised concerns about the long-term viability of its populations, but the stability responses of bull kelps to anthropogenic disturbances are still unclear. Here, we conducted a manipulative field experiment in which we removed once all individuals of the bull kelp from two sites in southern Chile. We simulated the loss of bull kelps to harvesting in 1-m2-plots interspersed in matrices of dense D. incurvata stands. Fronds cannot regrow from the holdfasts after harvesting. Holdfasts were therefore also removed, a practice not typically carried out by local gatherers. For 25 months we quantified bull kelp recruitment, holdfast densities, percent cover, mean frond size and density, biomass, and population size structure in two rocky intertidal sites. In both sites, all metrics completely recovered within five to seven months. The removal of D. incurvata did not have a significant impact on recruitment, which was constant during the experiment. The relatively small spatial scale of the disturbances, constant recruitment provided by the surrounding bull kelp matrix, and the removal of holdfasts that released settlement substratum may have allowed for the strong stability responses in these populations. Therefore, spatial heterogeneity, which allows for settles to colonize the disturbed plots, should be prioritized in management strategies of natural seaweeds stands.

ecology↗

bioRxiv2021

DNA reconciles morphology and colouration in the drunk blenny genus Scartichthys (Teleostei: Blenniidae) and provides insights into their evolutionary history

The blenniids of the genus Scartichthys are one of the most common fishes of Central and South American Pacific coastal reefs. This being said, Scartichthys spp. remain difficult to identify in the field, and identification is particularly challenging across the ca. 6000 km where three of the four currently accepted species are known to occur in sympatry. A reason for this is that the main taxonomic characters from traditional taxonomy are indeed elusive. Additionally, At the same time, species can display multiple colour patterns in the field, depending on their ontogenetic stage, habitat association, and reproductive behaviour. Overall, molecular characterization is warranted to help address these issues. Here, we have used a novel approach to revise the genus by combining colouration, morphological, and molecular data of representative specimens of the four currently valid species and seven described colour patterns. From this, we show that only three of the four species should be considered as valid; Scartichthys gigas (Steindachner, 1876), S. variolatus (Valenciennes, 1836), and S. viridis (Valenciennes, 1836); while S. crapulatus Williams 1990 should be synonymized with S. viridis. In the same way, our analyses show that one of the colour patterns attributed so far only to S. gigas is characteristic of the juvenile stages of S. viridis. Our time-calibrated phylogeny shows that this genus is relatively young and that the estimated time of divergence between Scartichthys gigas and S. viridis is around 1.71 Ma. In comparison, the Desventuradas and Juan Fernandez Islands endemic S. variolatus diverged about 1.95 Ma. Our results help to clarify the taxonomy of Scartichthys. SIGNIFICANCE STATEMENTThe blenniids of the genus Scartichthys are one of the most common fishes of Central and South American Pacific coastal reefs. Here we provide an updated phylogeny of this genus, comparing for the first time morphological, coloration, and molecular data in combination to resolve a 30-year-old discord among ecologists and taxonomists and discuss the potential underlying evolutionary processes that led to their presentday distribution.

zoology↗

bioRxiv2020

Alteration of coastal productivity and artisanal fisheries interact to affect a marine food-web

Top-down and bottom-up forces determine ecosystem function and dynamics. Fisheries as a top-down force can shorten and destabilize food-webs, while climate-change driven effects can alter the bottom-up forces of primary productivity. We assessed the response of a highly-resolved intertidal food-web to these two global-change drivers, using network analysis and bioenergetic modelling. We quantified the relative importance of artisanal fisheries as another predator species, and evaluated the independent and combined effects of fisheries and plankton-productivity changes on food-web dynamics. The food-web was robust to the loss of all harvested species but sensible to plankton-productivity decline. Interestingly, fisheries dampened the negative impacts of decreasing plankton productivity on non-harvested species, while plankton-productivity decline increased the sensitivity of harvested species to fishing. Our results show that strategies for new scenarios caused by climate change are needed to protect marine ecosystems and the wellbeing of local communities dependent on their resources.

ecology↗