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Hard coral coverage contributes to increasing the structural complexity of coral reefs, provides biological resources and drives biological and ecological interactions among reef organisms. Declines in the structural complexity and coral diversity of tropical reefs, due to the influence of anthropogenic activities, have been reported around the world in recent decades; however, coral reefs on the continental coast of Ecuador have been poorly studied. From September 2017 to April 2018, the method of permanent belt transects and quadrats was used to assess the status of coral (percentage of live, dead and fractured coral) to determine the contribution of derelict fishing gear to the process of coral fracture, which causes loss of structural complexity on two marginal coral-rocky reefs in the central coast of Manabi-Ecuador: Perpetuo Socorro and Ureles. Three geomorphological zones [crest (5–7 m depth), slope (7–10 m depth) and bottom (10–13 m depth)] were assessed. Results show that the crest zone in Ureles reef was highly affected by the entanglement of nets compared with Perpetuo Socorro, and identify derelict fishing gear as a key driver in the process of the fracturing and fragmentation of coral. Seasonal and site-associated factors also had a significant effect on the structural complexity of the reef studied. Destruction of coral in the crest zones drastically affects invertebrate and fish communities. We recommend a periodical assessment to measure the loss of structural complexity plus the implementation of a recovery program for the reefs studied that involves the education, active participation and collaboration of artisanal fishermen, governmental organizations and universities. [ABSTRACT FROM AUTHOR]

Natural and human-induced stressors have threatened the sustainability of the fish communities of coral-rocky reefs worldwide in the last decades. The composition of the fish communities on the reefs of Ecuador and the factors affecting spatiotemporal changes are unknown. We studied the influence of the descriptors of structural complexity, the current status of coral and human-induced variables over fish communities. A video transect method was used to assess fish communities in three zones (slope, crest, and bottom) of two reefs during two seasons (rainy and dry). The structure of fish communities was highly influenced by the zones and season; rugosity and live coral affected the fish composition on the crest and slope zones. The fractured coral and derelict fishing gear on coral produced an adverse effect on fish composition over the crest. A multifactorial process causing loss of structural complexity and affecting fish composition was identified, however, periodical assessment is required for a greater understanding of this process. Unlabelled Image • Differences in the fish composition between the study sites, zones and seasons. • High presence and prevalence of derelict fishing gear.on the coral colonies on the crests. • Negative effects over fish composition in relation to derelict fishing gear and fractured coral. • Spatial and temporal changes in fish communities driven by a multifactorial degradation process. • Evidence of a possible major threat of habitat degradation to coral-dependent fish populations. [ABSTRACT FROM AUTHOR]

The nesting environment is known to significantly affect the breeding success of sea turtles. Sandy beach habitats, where sea turtles nest, are frequently affected by high tides and waves on Ecuadorian beaches during windy events. The objectives of this study were: i) to determine the variables that affect nest site selection by two sea turtle species, Eretmochelys imbricata and Chelonia mydas in Ecuador, ii) to compare features of the nesting places of successful vs. failed clutches and iii) to quantify the changes in the intensity and frequency of the tide and its relation to the loss of eggs for the last 10 years. We monitored 15 hawksbill and 26 green turtle nests for two years on five beaches on the mainland coast of Ecuador. The results show that the presence of a dune scarps negatively affected successful nesting, while the proportion of eggs lost was positively associated with road distance, sea distance and nest depth. In addition, the results showed that the loss of eggs was greater for the green turtle, the presence of dune scarps and tides. Finally, using the data available on hatching success over the last 10 years we found a significant relationship between the intensity of the tides and the loss of eggs during this period. We conclude that nest site selection and hatching success vary with beach microhabitats and therefore local information is needed to protect suitable habitats. [ABSTRACT FROM AUTHOR]

• Differences in fish species richness and abundance depending on the sampling method. • Video-transect method was more efficient to assess the study variables. • Visibility significantly affected fish species richness and abundance. • Fish abundance was more affected by visibility in both sampling methods. • Visibility is a key factor for evaluating fish communities of rocky reefs. The effectiveness of using standardized sampling methods for fish communities in coral and rocky reefs has been widely discussed because it largely depends on the experience and skill of the observer, availability of high-definition equipment and the stability of local environmental parameters. The rocky reefs in Ecuador have highly variable conditions of turbidity, which can generate biases in the sampling of reef fish. The present work compares the effectiveness of detection of two sampling methods: 1) observer-band transects and 2) video-transects, as tools to determine the composition of fish communities in two rocky reefs subjected to high anthropic pressure and high variability in the conditions of turbidity. To achieve this goal, 48 transects of 100 m and variable-width on the dependence of turbidity conditions were performed in three geomorphological reef zones: the crest, slope, and bottom, where a community of fish was sampled from September 2017 to April 2018 using both methods. The results showed significant differences in the fish abundance recorded depending on the sampling method, the video-transect method was more efficient for the estimation of abundance. Comparison of the survey methods in reef zones showed that video-transects are more effective in detecting significant differences in abundance on the slopes of the reefs in comparison with observer-band transects. Turbidity significantly affected the abundance of fish detected by both sampling methods. Our results suggest that the video-transect method is more efficient to record fish abundance with respect to the observer-transect method under different conditions of turbidity. [ABSTRACT FROM AUTHOR]