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Adaptive movement in response to individual interactions represents a fundamental evolutionary solution found by both unicellular organisms and metazoans to avoid predators, search for resources or conspecifics for mating, and engage in other collaborative endeavors. Displacement processes are known to affect interspecific relationships, especially when linked to foraging strategies. Various displacement phenomena occur in marine plankton, ranging from the large-scale diel vertical migration of zooplankton to microscale interactions around microalgal cells. Among these symbiotic interactions, collaboration between the centric diatom Chaetoceros coarctatus and the peritrich ciliate Vorticella oceanica is widely known and has been recorded in several studies. Here, using 2D and 3D tracking records, we describe the movement patterns of the non-motile, chain-forming diatoms (C. coarctatus) carried by epibiotic ciliates (V. oceanica). The reported data on the Chaetoceros–Vorticella association illustrated the consortium's ability to generate distinct motility patterns. We established that the currents generated by the attached ciliates, along with the variability in the contraction and relaxation of ciliate stalks in response to food concentration, resulted in three types of trajectories for the consortium. The characteristics of these distinct paths were determined using robust statistical methods, indicating that the different displacement behaviors allowed the consortium to adequately explore distributed resources and remain within the food-rich layers provided in the experimental containers. A simple mechanical–stochastic model was successfully applied to simulate the observed displacement patterns, further supporting the proposed mechanisms of collective response to the environment. [ABSTRACT FROM AUTHOR]

Ultrasound waves have been employed to control marine biofouling but their effects on fouling organisms remain poorly understood. This study investigated the influence of ultrasound waves on barnacle (Tetraclita stalactifera cyprid larvae) pre-settlement behavior. Substrate inspection constituted most of the larval time budget, with a focus on the bottom surface rather than lateral or air–water interfaces. The frequency of substrate inspection decreased at 10 kPa when compared to higher acoustic pressures, while the time spent in the water column had an opposite trend. Various larval swimming modes were observed, including rotating, sinking, walking, and cruising, with rotating being dominant. Barnacle larvae exhibited higher speeds and less complex trajectories when subjected to ultrasound in comparison to controls. The impact of ultrasound waves on barnacle cyprid larvae behavior had a non-linear pattern, with lower acoustic pressure (10 kPa) inducing more effective substrate rejection than higher (15 and 20 kPa) intensities. [ABSTRACT FROM AUTHOR]

The dusky grouper (Epinephelus marginatus) is a vulnerable predatory fish found in the Atlantic and Indian oceans, and in the Mediterranean Sea. This study investigates the movement patterns of grouper larvae (151 individuals) during their first feeding period (three to ten days post hatching) through laboratory experiments offering rotifers (Brachionus sp.) and copepod nauplii as food. High-speed cameras and imaging techniques including bright field microscopy, matched filters, and holography captured rapid displacements (up to 25 body lengths per second), peduncle caudal beats (up to 40 beats s−1), turns, and resting periods. Reynolds numbers ranged from <45 for routine swimming to 222 for burst swimming. Specific behaviors, including changes in swimming velocity and body movements, were observed from three days post hatching, when feeding begins, suggestive of an array of responses to environmental forcing, predator avoidance, food search, and feeding success. These findings provide insights into the critical movement performances of E. marginatus larvae, which help to unravel their ecological interactions and survival strategies. Understanding grouper larval swimming behavior is pivotal for devising effective cultivation strategies aimed at replenishing wild stocks and enhancing production for human consumption. [ABSTRACT FROM AUTHOR]

Sun corals, Tubastraea spp., are native to the Indo-Pacific Ocean, but have established populations in different areas of the Atlantic Ocean. Tubastraea spp. are considered invasive in Brazil, being targets of a National Plan for Prevention, Control and Monitoring. One of the objectives of this plan is to develop scientific research and technology, focused on subsidies for the prevention and management of sun coral dissemination. Through manipulative experiments under controlled laboratory conditions, we analyzed the effects of exposure to air in sun coral colonies during different time intervals, to provide general biosecurity subsidies for possible management operations using desiccation. In addition, we recorded the coral ability to regenerate soft tissues damaged after trauma due to desiccation. We observed that Tubastraea sp. resists up to four hours out of seawater without permanent damage, despite being a typical subtidal organism. The number and severity of wounds and loss of soft tissues increased with exposure time to air, which affected the recovery capacity of this coral. Full mortality of the colonies (all polyps dead) was achieved only after four days of exposure to air. In addition, the healing regeneration process was recorded here for the first time in sun corals. The proportion of polyps partially retaining soft tissues involved in feeding is determining for the recovery of the entire colony, which can occur in just two weeks. Such data offer relevant biosecurity subsidies for possible management operations using desiccation. [ABSTRACT FROM AUTHOR]

The interaction between biological and short-term physical processes affects plankton distribution and composition variability, with consequences for the entire ecosystem. Aspects of the plankton distribution at smaller scales have been understudied, mainly in coastal regions where highly variable conditions promote variations in the biophysical environment. This work aimed to investigate the short-term variations in the distribution of plankton along the inner shelf off Ubatuba, Brazil. We quantified the abundance and diversity of the main planktonic taxa (>100 μm) and their spatiotemporal distribution in winter 2018 and summer 2019 using high-resolution sensors and a shadowgraphic imaging system at cross-shore and fixed stations (12 and 24 h). Summer–winter environmental contrast was evident in the water column stability and plankton abundance. In the summer, higher values of plankton abundance and diversity were obtained. Our results suggested that spatiotemporal variations related to wind-induced mixing and water mass intrusions lead to variabilities in plankton populations on a time scale of a few hours, vertically between depth layers and at spatial scales ˂2 km. This study contributes to the knowledge of the mechanisms of biophysical interactions and their spatiotemporal variation, which is crucial for assessing the effects of climate variability on plankton-mediated ecosystem services. [ABSTRACT FROM AUTHOR]

This document is a collection of articles from the journal Ocean & Coastal Research, focusing on the environmental variability and hazards in the coastal and continental shelf regions of South America and the Caribbean. The collection includes original research articles and brief communications covering topics such as ocean physics, biogeochemistry, coral reefs, marine protected areas, and the effects of oil spills. The aim of the collection is to improve understanding of these regions and the threats they face. The articles in this collection specifically focus on studies conducted in coastal South America, particularly in Brazil, and provide valuable information on the complex interactions in marine ecosystems and the importance of addressing threats to coastal environments. [Extracted from the article]

This study reports on the abundance, biomass and reproductive traits of Oncaea venusta , a common pelagic copepod in tropical oceans, in a coastal area influenced by bottom intrusions of the cold and nutrient-rich South Atlantic Central Water (SACW). In addition to O. venusta abundance and biomass, we estimated egg production and weight-specific fecundity rates by applying the egg-ratio method and incubation experiments, at monthly intervals over 3 years (July 2005–June 2008), to understand potential SACW influences on reproductive patterns. Mean abundance and biomass were low, and no differences were detected with and without SACW intrusions. Mean clutch size (±SD) was 65.1 ± 28.9 eggs female−1 and egg production rates averaged 7.6 ± 12.4 and 9.3 ± 5.2 eggs female−1 day−1 (viability >80%), for the egg-ratio method and incubation experiments, respectively, corresponding to a female weight-specific fecundity from 0.03 ± 0.05 to 0.04 ± 0.06 day−1. Oncaea venusta abundance and biomass were positively correlated with temperature, but no SACW influence on the reproductive rates was recorded. The egg production rate and the female weight-specific fecundity were influenced by the chlorophyll a concentration and the sex ratio. Although egg production and female weight-specific fecundity rates had peak values during intrusion events, no immediate impact on population abundance was observed within the same time interval. [ABSTRACT FROM AUTHOR]