scholarly journals Reduced fish diversity despite increased fish biomass in a Gulf of California Marine Protected Area

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8885
Author(s):  
Georgina Ramírez-Ortiz ◽  
Héctor Reyes-Bonilla ◽  
Eduardo F. Balart ◽  
Damien Olivier ◽  
Leonardo Huato-Soberanis ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Fish Assemblages ◽  
Marine Protected Area ◽  
Marine Conservation ◽  
Primary Objective ◽  
Fish Diversity ◽  
Fishing Pressure ◽  
General Increase ◽  
Functional Richness ◽  
Density And Biomass

Multi-use marine protected areas (MUMPAs) are a commonly applied tool for marine conservation in developing countries, particularly where large no-take reserves are not socially or politically feasible. Although MUMPAs have produced benefits around the world, the persistence of moderate fishing pressure reduces the likelihood of achieving the primary objective of these areas, which is the conservation of ecosystems. In this study we used traditional and functional metrics to evaluate how fish assemblages changed through time in a MUMPA, including shifts in species responses and in ecological processes. We conducted visual censuses of fishes at Espíritu Santo Island, México (MUMPA; N = 320; 24°N, 110°W) from 2005 to 2017 to assess fish richness, size-distribution and density. Three functional indices were calculated using six traits (size, mobility, period of activity, aggregation, position in water column and diet): functional richness (volume occupied by species), dispersion (complementarity between species) and originality (inverse of functional redundancy). We compared fish diversity among three management zone types (sustainable fishing, traditional fishing and no-take zones), through a 13-year period, assessing which species increased or decreased in occurrence, density, and biomass, and how indices respond over time. Despite a general increase in biomass and stability in density and originality, we detected a reduction in fish biodiversity in the form of declines in species and functional richness, which could imply the risk of local extinction and decrease in certain ecosystem processes. In addition, changes in functional dispersion showed that some functions are losing representation through time. Although no single cause is apparent, such factors as competitive interactions, habitat loss and persistence of fishing pressure potentially explain these decreases. The rise in biomass was associated with a general increase in the average size, rather than increased biomass of commercial species, as the latter remained stable during the study period. Expansion of no-take areas, enforcement of fishing regulations, and surveillance in core zones, should be implemented to reverse the decline in particular species and to promote conservation of fish functional diversity in this MUMPA.

scholarly journals Linking Habitat and Associated Abiotic Conditions to Predict Fish Hotspots Distribution Areas within La Paz Bay: Evaluating Marine Conservation Areas

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 212
Author(s):  
Francisco Javier Urcádiz-Cázares ◽  
Víctor Hugo Cruz-Escalona ◽  
Mark S. Peterson ◽  
Rosalía Aguilar-Medrano ◽  
Emigdio Marín-Enríquez ◽  
...  
Keyword(s):  
Gulf Of California ◽  
Management Plan ◽  
Marine Conservation ◽  
Fish Diversity ◽  
Rocky Shores ◽  
Conservation Areas ◽  
Niche Modelling ◽  
La Paz ◽  
Abiotic Conditions ◽  
Presence Data

Hotspots are priority marine or terrestrial areas with high biodiversity where delineation is essential for conservation, but equally important is their linkage to the environmental policies of the overall region. In this study, fish diversity presences were linked to abiotic conditions and different habitat types to reveal multi-species and hotspots models predicted by ecological niche modelling methods within the Bay of La Paz, Mexico (south of Gulf of California). The abiotically suitable areas for 217 fish species were identified based on historical (1975–2020) presence data sets and a set of environmental layers related to distances from mangroves and rocky shores habitats, marine substrate, and bottom geomorphology conditions. Hotspot model distribution was delineated from a multi-species model identifying areas with ≥60 species per hectare and was compared to the marine conservation areas such Balandra Protected Natural Area (BPNA), illustrating how these models can be applied to improve the local regulatory framework. The results indicate that (1) there is a need for the BPNA to be enlarged to capture more of the delineated hotspot areas, and thus an update to the management plan will be required, (2) new conservation areas either adjacent or outside of the established BPNA should be established, or (3) Ramsar sites or other priority areas should be subject to legal recognition and a management plan decreed so that these vital habitats and fish diversity can be better protected.

scholarly journals Adaptive capacity of reef-associated fishes to Climate Change

2018 ◽  
Author(s):  
Marina Abas ◽  
Hector Reyes-Bonilla
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Fish Species ◽  
Gulf Of California ◽  
Census Data ◽  
Fish Assemblages ◽  
Reef Fishes ◽  
Marine Conservation ◽  
Eastern Pacific ◽  
Tropical Region

Climate change is affecting the structure and function of marine communities in the eastern Pacific, and to anticipate possible consequences of these modifications, a better understanding of the natural adaptation potential of the species is needed. This study aimed to build a metric of adaptive capacity of reef fishes, and evaluate it using data from fish assemblages from 12 rocky and coral reefs of western Mexico. The index was developed using six life history traits from 719 fish-species distributed along the tropical Eastern Pacific. Our results indicated low adaptive capacity for big sized carnivore fish such as the tunas, totoaba and most groupers (Mycteroperca spp.); conversely, high values were attributed to species with fast life strategies such as anchovies, gobies, and blennies. The application of the index to census data showed that the adaptive potential of fish assemblages had an inverse latitudinal trend (higher in the southern reefs), resulting from the abundance of large-sized carnivores in the central and northern Gulf of California, and of small herbivores in the tropical region. As the index allows to estimate reef-fish species and communities' adaptive capacity in a straightforward and simple way, it may be a useful tool for marine conservation.

scholarly journals Adaptive capacity of reef-associated fishes to Climate Change

2018 ◽  
Author(s):  
Marina Abas ◽  
Hector Reyes-Bonilla
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Fish Species ◽  
Gulf Of California ◽  
Census Data ◽  
Fish Assemblages ◽  
Reef Fishes ◽  
Marine Conservation ◽  
Eastern Pacific ◽  
Tropical Region

Climate change is affecting the structure and function of marine communities in the eastern Pacific, and to anticipate possible consequences of these modifications, a better understanding of the natural adaptation potential of the species is needed. This study aimed to build a metric of adaptive capacity of reef fishes, and evaluate it using data from fish assemblages from 12 rocky and coral reefs of western Mexico. The index was developed using six life history traits from 719 fish-species distributed along the tropical Eastern Pacific. Our results indicated low adaptive capacity for big sized carnivore fish such as the tunas, totoaba and most groupers (Mycteroperca spp.); conversely, high values were attributed to species with fast life strategies such as anchovies, gobies, and blennies. The application of the index to census data showed that the adaptive potential of fish assemblages had an inverse latitudinal trend (higher in the southern reefs), resulting from the abundance of large-sized carnivores in the central and northern Gulf of California, and of small herbivores in the tropical region. As the index allows to estimate reef-fish species and communities' adaptive capacity in a straightforward and simple way, it may be a useful tool for marine conservation.

scholarly journals Free-diving underwater fish photography contests: a complementary tool for assessing littoral fish communities

2018 ◽  
Vol 82 (2) ◽  
pp. 95 ◽  
Author(s):  
Ana Gordoa ◽  
Jordi Boada ◽  
Antoni García-Rubies ◽  
Oscar Sagué
Keyword(s):  
Species Richness ◽  
Protected Area ◽  
Fish Assemblages ◽  
Marine Protected Area ◽  
Fish Communities ◽  
Cost Effective ◽  
Fish Diversity ◽  
Littoral Fish ◽  
Potential Tool ◽  
Image Frequency

Characterizing fish communities must be a priority to safeguard resources and determine critical changes. Here, species richness and the spatial and temporal evolution in the structure of fish assemblages were analysed based on photos taken in underwater free-diving contests. A total of 29 contests held from 2008 to 2015 at four different locations along the northeastern Spanish coast, including a marine protected area were analysed. Contests reward the number of species per participant and photographic quality. Species image frequency from each tournament were standardized to catch image rate. A total of 88 taxa were recorded, including 32 cryptobenthic species, the highest number recorded in the Mediterranean littoral system so far. Cluster analyses yielded four major groups. Catch image rates in the marine protected area were significantly higher for seven species of high commercial interest and for two big labrids of recreational interest, including an endangered species (Labrus viridis). Overall, the study showed that photographic free-diving contest data are a potential tool for determining species richness in littoral systems since contest rules promote competition between participants to obtain maximum fish diversity. We believe that this type of cost-effective data can be applied worldwide as a complementary way of monitoring littoral fish assemblage.

scholarly journals Early conservation benefits of a de facto marine protected area at San Clemente Island, California

2019 ◽  
Author(s):  
Michael W. Esgro ◽  
James Lindholm ◽  
Kerry J. Nickols ◽  
Jessica Bredvik
Keyword(s):  
Community Composition ◽  
Marine Protected Area ◽  
Marine Conservation ◽  
Marine Spatial Planning ◽  
Linear Modeling ◽  
Remotely Operated Vehicle ◽  
Marine Habitats ◽  
Potential Benefits ◽  
Density And Biomass ◽  
San Clemente Island

AbstractDe facto marine protected areas (DFMPAs) are regions of the ocean where human activity is restricted for reasons other than conservation. Although DFMPAs are widespread globally, their potential role in the protection of marine habitats, species, and ecosystems has not been well studied. In 2012 and 2013, we conducted remotely operated vehicle (ROV) surveys of marine communities at a military DFMPA and an adjacent fished reference site at San Clemente Island, the southernmost of California’s Channel Islands. We used data extracted from ROV imagery to compare density and biomass of focal species, as well as biodiversity and community composition, between the two sites. Generalized linear modeling indicated that both density and biomass of California sheephead (Semicossyphus pulcher) were significantly higher inside the DFMPA. Biomass of ocean whitefish (Caulolatilus princeps) was also significantly higher inside the DFMPA. However, species richness and Shannon-Weaver diversity were not significantly higher inside the DFMPA, and overall fish community composition did not differ significantly between sites. Demonstrable differences between the DFMPA and fished site for two highly sought-after species hint at early potential benefits of protection, though the lack of differences in the broader community suggests that a longer trajectory of recovery may be required for other species. A more comprehensive understanding of the potential conservation benefits of DFMPAs is important in the context of marine spatial planning and global marine conservation objectives.

scholarly journals Adaptive capacity of reef-associated fishes to Climate Change

2018 ◽  
Author(s):  
Marina Abas ◽  
Hector Reyes-Bonilla
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Fish Species ◽  
Gulf Of California ◽  
Census Data ◽  
Fish Assemblages ◽  
Reef Fishes ◽  
Marine Conservation ◽  
Eastern Pacific ◽  
Tropical Region

Climate change is affecting the structure and function of marine communities in the eastern Pacific, and to anticipate possible consequences of these modifications, a better understanding of the natural adaptation potential of the species is needed. This study aimed to build a metric of adaptive capacity of reef fishes, and evaluate it using data from fish assemblages from 12 rocky and coral reefs of the western Mexico. The index was developed using six life history traits from 719 fish-species distributed along the tropical Eastern Pacific. Our results indicated low adaptive capacity for big sized carnivore fish such as the tunas, totoaba and most groupers (Mycteroperca spp.); conversely, high values were attributed to species with fast life strategies such as anchovies, gobies, and blennies. The application of the index to census data showed that the adaptive potential of fish assemblages had an inverse latitudinal trend (higher in the southern reefs), resulting from the abundance of large-sized carnivores in the central and northern Gulf of California, and of small herbivores in the tropical region. As the index allows to estimate reef-fish species and communities' adaptive capacity in a straightforward and simple way, it may be a useful tool for marine conservation. conservation.

FISH DIVERSITY IN THE DOWNSTREAM REGION OF CIPANAS RIVER INDRAMAYU, WEST JAVA INDONESIA

Zoo Indonesia ◽  
2020 ◽  
Vol 29 (1) ◽  
Author(s):  
Titin Herawati ◽  
Gema Wahyudewantoro ◽  
Yuli Andriani ◽  
Heti Herawati ◽  
Naomi Masnida Yunisia Siregar
Keyword(s):  
Water Quality ◽  
Census Data ◽  
Fish Assemblages ◽  
Survey Methods ◽  
Upstream Region ◽  
Fish Diversity ◽  
West Java ◽  
Fish Collection ◽  
Java Sea ◽  
Downstream Area

Cipanas River is one river in West Java where its upstream region in Tampomas Mountain, Sumedang and it is emptied into the Java Sea, Indramayu. The study was aimed to investigate fish diversity in the downstream area of Cipanas River. The study was conducted by survey methods with census data collection techniques, taken place at 3 stations of Santing, Tempalong, and Cemara of Indramayu Regency. The parameters measured consisted water quality and fish assemblages. Water quality was measured referring to standard laboratory protocol, and fish collection was made by case net with different mesh sizes. The results showed that water quality conditions of the Cipanas River downstream was suitable for inhabiting fishes. There were as many as 548 individual fishes caught belonging to 21 species, 16 genera, and 14 families. Fish diversity was categorized as medium with 1.6 ≤ H ’≤ 2.2 indicating fairly good community structure, and the Evenness index was 0.81 ≤ E ≤ 0.86 to show highly evenly distributed.

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