The beach-seine fishery off durban, Kwazulu-Natal

The beach-seine fishery at Durban was investigated from July 1993 to June 1994. During this period the fishermen completed 270 hauls on 146 days of operation. In total, 119 species of fish as well as squid, cuttlefish and crabs were recorded in the catches. Most of these were small shoaling species belonging to the families Leiog-nathidae, Engraulidae and Clupeidae. Many species were caught at sizes below their reported size at first maturity. Based on this study and data from the National Marine Linefish System, there appears to be little overlap in the catches of the beach-seine netters and other fishery sectors in the area

Lifting back the waters: Marine geophysics provides new insights into the uThukela Banks Marine Protected Area

Using the first high-resolution geophysical data set collected from the uThukela Banks Marine Protected Area (MPA), we reveal a plethora of hitherto unknown or poorly resolved seabed features. In tandem with several remotely operated vehicle dives, we improve on the previous National Biodiversity Assessment map for the area and reveal a more complex picture of the seabed geology and geomorphology on which the MPA is predicated. The upper slope (-120 m and deeper) is dominated by small canyons, gullies and rills that occasionally extend to the shelf edge and form a series of slumps. Suspected cold-water corals were imaged on the interfluves of the Thukela Canyon. The mid to outer shelf (-60 to -100 m) is mostly rocky, and is composed of Pliocene-age siltstones for the most part. Aeolianite shorelines are found at depths of 60 m and 100 m, in which palaeo-lagoons and parabolic aeolian dune systems are also preserved. These features provide habitat for mesophotic corals and demersal fishes. Overlying and abutting hard rock substrates are unconsolidated sandy sediments that are mobilised by the inshore movement of the Agulhas Current. An inshore mud belt characterised by pockmarks associated with free gas expulsion is mapped for the first time. A well-developed palaeo-drainage pattern is also revealed, posing exciting new opportunities for the study of benthic communities associated with palaeo-estuaries and lagoons now exposed at the seabed. Several new habitats, both inside and out of the MPA boundaries, should form the basis for future research within the MPA, in addition to informing expansions of the MPA. Significance: Using a newly collected geophysical data set, we provide an unprecedented glimpse into the newly proclaimed uThukela Banks Marine Protected Area. We reveal a complexity of marine habitats hitherto unknown from previous biodiversity surveys. These habitats include areas of possible expansion given the recognition of keystone species that occur just outside the MPA limits

Marine megafauna interactions with small-scale fisheries in the southwestern Indian Ocean: a review of status and challenges for research and management

In developing regions, coastal communities are particularly dependent on small-scale fisheries for food security and income. However, information on the scale and impacts of small-scale fisheries on coastal marine ecosystems are frequently lacking. Large marine vertebrates (marine mammals, sea turtles and chondrichthyans) are often among the first species to experience declines due to fisheries. This paper reviews the interactions between small-scale fisheries and vulnerable marine megafauna in the southwestern Indian Ocean. We highlight an urgent need for proper documentation, monitoring and assessment at the regional level of small-scale fisheries and the megafauna affected by them to inform evidence-based fisheries management. Catch and landings data are generally of poor quality and resolution with compositional data, where available, mostly anecdotal or heavily biased towards easily identifiable species. There is also limited understanding of fisheries effort, most of which relies on metrics unsuitable for proper assessment. Management strategies (where they exist) are often created without strong evidence bases or understanding of the reliance of fishers on resources. Consequently, it is not possible to effectively assess the current status and ensure the sustainability of these species groups; with indications of overexploitation in several areas. To address these issues, a regionally collaborative approach between government and non-governmental organisations, independent researchers and institutions, and small-scale fisheries stakeholders is required. In combination with good governance practices, appropriate and effective, evidence-based management can be formulated to sustain these resources, the marine ecosystems they are intrinsically linked to and the livelihoods of coastal communities that are tied to them

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Metabarcoding of ichthyoplankton communities associated with a highly dynamic shelf region of the southwest Indian Ocean.

Drifting fish eggs and larvae (ichthyoplankton) can be identified to species using DNA metabarcoding, thus allowing for post hoc community analyses at a high taxonomic resolution. We undertook a regional-scale study of ichthyoplankton distribution along the east coast of South Africa, focused on the contrasting environments of the tropical Delagoa and subtropical Natal Ecoregions, and on exposed and sheltered shelf areas. Zooplankton samples were collected with tow nets at discrete stations along cross-shelf transects (20-200 m depth) spaced along a latitudinal gradient that incorporates a known biogeographical boundary. Metabarcoding detected 67 fish species, of which 64 matched prior distribution records of fishes from South Africa, with the remaining three known from the Western Indian Ocean. Coastal, neritic and oceanic species were present, from epi- and mesopelagic to benthopelagic and benthic adult habitats. By family, Myctophidae (10 species), Carangidae, Clupeidae, Labridae (each with 4 species) and Haemulidae (3 species) were most speciose. Ichthyoplankton community composition varied significantly with latitude, distance to coast, and distance to the shelf edge. Small pelagic fishes had the highest frequency of occurrence: Engraulis capensis, Emmelichthys nitidus and Benthosema pterotum increased in frequency towards the north, whereas Etrumeus whiteheadi increased towards the south. Chub mackerel Scomber japonicus accounted for most variability related to distance from the coast, whilst African scad Trachurus delagoa correlated with distance to the shelf edge. Dissimilarity between communities in the Delagoa and Natal Ecoregions was 98-100%, whereas neighbouring transects located within the sheltered KwaZulu-Natal Bight had lower dissimilarity (56-86%). Onshore transport of ichthyoplankton by Agulhas Current intrusions plausibly explained the abundance of mesopelagic species over the shelf. Metabarcoding followed by community analysis revealed a latitudinal gradient in the ichthyoplankton, associations with coastal and shelf-edge processes, and evidence of a spawning area in the sheltered KwaZulu-Natal Bight

Lifting back the waters: Marine geophysics provides new insights into the uThukela Banks Marine Protected Area

Using the first high-resolution geophysical data set collected from the uThukela Banks Marine Protected Area (MPA), we reveal a plethora of hitherto unknown or poorly resolved seabed features. In tandem with several remotely operated vehicle dives, we improve on the previous National Biodiversity Assessment map for the area and reveal a more complex picture of the seabed geology and geomorphology on which the MPA is predicated. The upper slope (-120 m and deeper) is dominated by small canyons, gullies and rills that occasionally extend to the shelf edge and form a series of slumps. Suspected cold-water corals were imaged on the interfluves of the Thukela Canyon. The mid to outer shelf (-60 to -100 m) is mostly rocky, and is composed of Pliocene-age siltstones for the most part. Aeolianite shorelines are found at depths of 60 m and 100 m, in which palaeo-lagoons and parabolic aeolian dune systems are also preserved. These features provide habitat for mesophotic corals and demersal fishes. Overlying and abutting hard rock substrates are unconsolidated sandy sediments that are mobilised by the inshore movement of the Agulhas Current. An inshore mud belt characterised by pockmarks associated with free gas expulsion is mapped for the first time. A well-developed palaeo-drainage pattern is also revealed, posing exciting new opportunities for the study of benthic communities associated with palaeo-estuaries and lagoons now exposed at the seabed. Several new habitats, both inside and out of the MPA boundaries, should form the basis for future research within the MPA, in addition to informing expansions of the MPA. Significance: Using a newly collected geophysical data set, we provide an unprecedented glimpse into the newly proclaimed uThukela Banks Marine Protected Area. We reveal a complexity of marine habitats hitherto unknown from previous biodiversity surveys. These habitats include areas of possible expansion given the recognition of keystone species that occur just outside the MPA limits