This study provides empirical data on the exploitation of fishery resources Sundays Estuary south-east coast South Africa. Total annual effort was estimated at 63 785 angler-hours, which accounted for an yield 16 214 fish (8.0 t). Effort and mean catch per unit exhibited seasonal trends were highest during summer. Dusky kob Argyrosomus japonicus spotted grunter Pomadasys commersonnii most commonly targeted species bulk catch: 3.4 t (43% gravimetrically, 22% numerically) 1.9 (24%...

The Acoustic Tracking Array Platform (ATAP) is a marine science programme that monitors the movements and migrations of inshore animals along South African coastline. Acoustically tagged are monitored by an expanded network approximately 100 automated data-logging acoustic receivers moored at strategic node sites, from Cape Point in west to Africa–Mozambique border east. During five years since its inception, 2011, ATAP has achieved outstanding progress terms numbers variety species tagged....

It has been suggested that tourism fisheries can raise the value of landed catch, provide alternative livelihoods for local artisanal fishers and, because recreationally caught fishes are often released, simultaneously conserve stocks. However, fishing to meet ecotourism standards, sustainable, economic benefit is imperative. This study aimed assess direct contribution recreational fishery Polydactylus quadrifilis on Kwanza Estuary, Angola. The contributed significantly productivity in an...

Coastal ecosystems serve as important nursery areas, yet they are facing many challenges. For example, eutrophication-induced hypoxia is one of the major threats to functioning coastal ecosystems, particularly estuaries. The Sundays and Swartkops estuaries both experience persistent eutrophic conditions, with frequent phytoplankton blooms (>20 μg Chl-a l−1) that result in instances bottom-water oxygen depletion (<4 mg/l). Bi-seasonal sampling physico-chemical parameters demersal fishes...

Abstract The spatial and temporal area-use patterns of estuarine-dependent juvenile dusky kob Argyrosomus japonicus in the Great Fish Estuary, South Africa, were examined using acoustic telemetry. In all, 29 individuals (307–400 mm total length) surgically equipped with individually coded transmitters monitored for a period up to 195 days an array 11 moored data-logging receivers. Tagged spent most time estuary (84%), compared neighbouring marine (13%) riverine (4%) environments. fish made...

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 537:233-245 (2015) - DOI: https://doi.org/10.3354/meps11456 Habitat connectivity and intra-population structure of an estuary-dependent fishery species Amber-Robyn Childs1,2,*, Paul D. Cowley1,2**, Tor F. Næsje2,3, Rhett H. Bennett2 1Department Ichthyology Fisheries Science, Rhodes University, Grahamstown...

Abstract The characteristics and contribution of a developing recreational fishery to the local, regional national economy Angola were evaluated in 2006. Annual angling effort was 13 435 h, while estimated total catch three target species [leerfish, Lichia amia (L.), west coast dusky kob, Argyrosomus coronus (Griffiths &amp; Heemstra) shad, Pomatomus saltatrix (L.)], 5913 fish with mass 27 975 kg. Catch per unit (CPUE) for all teleost combined 0.44 angler h −1 2.08 kg . Total harvest 576...

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 460:221-232 (2012) - DOI: https://doi.org/10.3354/meps09780 Riding tide: estuarine movements of a sciaenid fish, Argyrosomus japonicus Tor Fredrik Næsje1,2,*, Paul Denfer Cowley2, Ola Håvard Diserud1, Amber-Robyn Childs2, Sven Ebo Kerwath3,4, Eva Bonsak Thorstad1 1Norwegian Institute for Nature Research, 7485...

Connectivity — movements of animals between and among numerous habitats the factors (rhythmic cycles environmental variables) influencing connectivity juvenile Lichia amia (Teleostei: Carangidae) were assessed in complementary acoustic telemetry studies two geographically separated estuaries (620 km apart) South Africa. The conducted within a nationwide array receivers moored coastal waters. Tagged fish both Kowie (n = 21) Goukou 17) displayed high levels multiple habitat connectivity, with...

Abstract Factors influencing estuarine use and marine excursions by spotted grunter Pomadasys commersonnii in the Great Fish Estuary, South Africa, were studied using manual automated telemetry methods. In all, 20 individuals, ranging from 362 mm to 698 total length (TL), caught tagged with acoustic-coded transmitters estuary. Tagged individuals spent most time estuary (67%), interspersed a number of — 15 all. The (6–53) mean duration (0.8–9.5 days) sea varied among correlated significantly...

Abstract Marine predators are vital to the healthy functioning of coastal ecosystems, but understand their roles, it is necessary elucidate movement ecology, particularly in relation one another. A decade's worth acoustic telemetry data (2011–2020) from Algoa Bay, South Africa, was investigated determine how two mesopredatory species (teleosts: dusky kob Argyrosomus japonicus , n = 11, and leervis Lichia amia 16) top predatory (sharks: ragged‐tooth sharks Carcharias taurus 45, white...

Abstract The home range and area use of spotted grunter, Pomadasys commersonnii (Haemulidae) (Lacepède), were investigated in the Great Fish estuary, South Africa. Forty individuals (263–698 mm TL) surgically implanted with acoustic‐coded transmitters manually tracked during two periods 2003. Tagged fish spent on average 68 77% time estuary remaining at sea periods, respectively. While there was large variation size, length number areas amongst individuals. Larger had larger ranges more core...

Abstract Elemental analysis of biological calcified structures (e.g. fish otoliths, mollusc shelves, coral skeletons or and shark bones) provides invaluable information regarding ecological processes for many aquatic species. Despite this importance, the reduction raw data obtained through Laser‐ablation Inductively Coupled Plasma Mass Spectrometry ( LA ‐ ICPMS ) (i.e. conversion machine signal into elemental concentrations) remains a challenge as tools developed so far carrying out task...

The Kariega Estuary in South Africa, is an example of a freshwater-deprived estuary. Large-scale water abstraction and droughts have resulted this estuary either being uniformly marine or hypersaline. A major episodic flood event October 2012, the largest ever recorded system, provided us with opportunity to investigate prolonged effect on demersal fish assemblage beam trawl net was used for sampling assemblages from December 2013 November 2014. before period ‘reset’ such that there...

Estuaries serve as important nursery habitats for several coastal fishery species. The successful recruitment of larvae and early juveniles into estuaries is paramount population persistence maintenance. Several factors have been proposed stimuli that could elicit a response in estuary-associated fish Larvae may trace land-based cues back to an estuary by following the olfactory concentration gradient or use other visual acoustic stimuli. Argyrosomus japonicus iconic estuarine-associated Due...

Biotelemetry is an increasingly popular and effective tool to study fish movements. Interpretation of the results relies on assumption that behaviour physiology not affected by presence tag. Although long-term effects tagging should be evaluated before field telemetry studies, this has rarely been quantified. As a precursor Argyrosomus japonicus (Termminck Schlegel 1843) in South Africa, surgical implantation two different-sized tags were assessed 256-day experiment. We hypothesised larger...

Seagrass habitats provide structural complexity in coastal estuarine and marine environments, which offer fish optimal foraging grounds refuge from predation. However, seagrasses are some of the most threatened ecosystems globally, with anthropogenic activities such as population growth environmental degradation leading to fragmentation, thinning, loss these habitats. Rhabdosargus holubi is one only a few vegetation-associated species South African estuaries. Although field studies have...

Quantifying how the heart rate of ectothermic organisms responds to environmental conditions (e.g. water temperature) is important information quantify their sensitivity change. Heart studies have typically been conducted in lab environments where fish are confined. However, commercially available implantable biologgers provide opportunity study free-swimming fish. Our aimed determine applicability an device, used on fusiform-shaped salmonids), for a perciform morphology and anatomy prevent...

Abstract Acoustic telemetry and long-term seine-netting data were used to assess distribution, area use, home range dynamics movement patterns of estuarine-dependent juvenile white steenbras Lithognathus lithognathus in the temporarily open/closed East Kleinemonde Estuary. Using 15 years biannual data, it was shown that abundance highest mouth region decreased with distance from mouth. Fifteen fish equipped acoustic transmitters monitored for eight months using an array stationary receivers,...