The blue stingray
Dasyatis chrysonota
is an important and endemic coastal inhabitant of southern African coastal waters however, it is listed as Near Threatened with declining populations. ...Understanding it’s spatial ecology in the context of current Marine Protected Areas (MPAs) is vital to not only inform population dynamics and ecological roles, but to determine whether currently zoned MPAs can provide sufficient protection to this species. Twenty-seven individuals were monitored using the Acoustic Tracking Array Platform (ATAP—a nation-wide collaborative network of acoustic receivers) for up to 4.5 years. Individuals displayed site affinity to defined regions of the coast, with the majority of detections for most individuals being recorded in the shallow bay/coastal shelf they were tagged in. However, important movement corridors linking different habitats were also identified (inshore vs offshore and coastal bay vs coastal shelf habitats). This habitat use varied monthly and was influenced by temperature, with individuals displaying restricted movements to the shallow bay habitat in summer when deeper waters were much colder. The large collaborative nature of the ATAP allowed for the monitoring of a benthic ray across large spatial scales for the first time, challenging preconceived notions that small undulatory batoids cannot travel large distances (many individuals were found to travel up to 200 km). Insights can also assist in local management of this species, and highlight that current MPA zonation may not be sufficient to protect blue stingrays from further population declines.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Many ray species are threatened with extinction, and so understanding their movement and habitat use is vital for developing effective management and conservation efforts. Globally, rays are known to ...rely on estuarine habitats, but estuary use by rays has not yet been investigated in South Africa. Thirty-three diamond rays
Gymnura natalensis
and 25 bull rays
Aetomylaeus bovinus
, both species anecdotally recorded to occur in estuaries, were acoustically tagged. Individuals were tracked using a nation-wide network of receivers in South Africa, the Acoustic Tracking Array Platform (ATAP), that has acoustic receivers in both marine and estuarine environments. Only six rays (4 diamond and 2 bull rays) were recorded using estuaries, but they displayed seasonal philopatry, returning to specific estuaries during spring to autumn months (September to May) for up to 6 consecutive years. Due to a number of rays entering the Breede Estuary, the fine-scale habitat use in this ecosystem was investigated. Marine-estuarine connectivity was significantly influenced by marine temperatures. Additionally, presence in the upper parts of the Breede Estuary (up to 17 km from the mouth) was influenced by temperature, tides and time of day. Findings suggest estuaries are an important, and previously overlooked, habitat type for a portion of the diamond and bull ray populations on the south coast of South Africa, which has management and conservation implications.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Marine predators are vital to the healthy functioning of coastal ecosystems, but to understand their roles, it is necessary to elucidate their movement ecology, particularly in relation to one ...another. A decade's worth of acoustic telemetry data (2011-2020) from Algoa Bay, South Africa, was investigated to determine how two mesopredatory species (teleosts: dusky kob Argyrosomus japonicus, n = 11, and leervis Lichia amia, n = 16) and two top predatory species (sharks: ragged-tooth sharks Carcharias taurus, n = 45, and white sharks Carcharodon carcharias, n = 31) used and shared this bay ecosystem. Multi-annual seasonal fidelity to the bay was exhibited by all species, but differences in residency were observed among species. Similarly, species used space in the bay differently-the teleosts moved less and had movements restricted to the central and western inshore regions of the bay. Conversely, the sharks roamed more, but detections were concentrated in the western part of the bay for C. taurus and in the eastern part of the bay for C. carcharias. Social network analysis showed that species segregated in space and time on a fine scale. However, there was some interaction observed between C. taurus, L. amia, and A. japonicus, but to varying degrees. This is likely because of strong habitat preferences exhibited by each species and predator-prey relationships between these predatory guilds. Results highlight that the sheltered marine Algoa Bay is a resource-rich environment, supporting multiple predators with different hunting strategies albeit similar prey preferences. Finally, these species are likely afforded some protection by the current Greater Addo Elephant National Park Marine Protected Area in the bay but are vulnerable to fishing pressure when they leave this ecosystem.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Migration is a critical aspect of ocean ecosystems, and understanding this phenomenon answers ecological and management questions. Given the difficulty in tracking ocean animals across large ...distances, the extent to which different ray species perform long-distance movements, such as migrations, remains unknown. This study used passive acoustic telemetry to track the movements of endemic diamond Gymnura natalensis and critically endangered duckbill Aetomylaeus bovinus rays along the South African coastline using a collaborative nationwide network of coastal acoustic receivers for up to 7 years. Duckbill rays were detected significantly more frequently than diamond rays, but both species moved between the south and east coasts of South Africa (traveling up to 1167 km). Tagged individuals were detected significantly more often in their tagging locations during summer months but traveled significantly further distances during winter months. Furthermore, movement models fitted to individual duckbill rays' annual net-squared displacement identified most individual annual movements as migratory. This evidence suggests that both diamond and duckbill rays make eastward winter migrations and return to specific areas along the coastline during the summer months. The exceptions to this were diamond rays tagged on the east coast that were not found to migrate seasonally, which supports previous research that there is intraspecific variability in migrations for ray species. These findings have implications for understanding ray migration not only on a global scale but also locally for spatial management interventions and population delineation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Connectivity--movements of animals between and among numerous habitats--and the factors (rhythmic cycles and environmental variables) influencing connectivity of juvenile Lichia amia (Teleostei: ...Carangidae) were assessed in complementary acoustic telemetry studies in two geographically separated estuaries (620 km apart) in South Africa. The studies were conducted within a nationwide array of acoustic receivers moored in estuaries and coastal waters. Tagged fish in both the Kowie (n = 21) and Goukou (n = 17) estuaries displayed high levels of multiple habitat connectivity, with 81% and 76% visiting nearby marine and estuarine environments, respectively. The presence of tagged L. amia within the tagging estuaries was significantly influenced by river and sea temperature (Kowie) and river inflow and moon phase (Goukou). Tidal phase, time of day, and season were found to significantly influence marine excursions undertaken by Kowie- and Goukou-tagged fish. Our study provides an assessment of connectivity among multiple estuarine, port, and marine habitats, relating those movements to rhythmic cycles and environmental variables, and highlights the benefits of tracking animals using an extensive acoustic receiver array that spans multiple habitats.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Giant trevally Caranx ignobilis are iconic, apex marine predators globally distributed in tropical to subtropical regions, where they are of high importance to ecosystems and fisheries. During ...summer, adults aggregate for spawning, making them vulnerable to overfishing. The world’s largest C. ignobilis aggregation has been recorded in southern Mozambique, but the year-round movements of these fish required further investigation. To assess movement patterns of C. ignobilis along the southern African coast, 36 adult fish were acoustically tagged and monitored along the east coast between Santa Maria in southern Mozambique and Port St Johns in the Eastern Cape, South Africa, for over 5 yr using an extensive passive acoustic receiver array. All acoustically tagged C . ignobilis were recorded in southern Mozambique between November and January each year (with minor exceptions), moving distances up to a maximum of 632 km in one direction. These movements were fast and direct, with maximum travelling speeds of up to 130 km d -1 . When not migrating, South African-based fish showed consistent inter-annual fidelity to individual linear areas of space use equivalent to home ranges. Although the coastal length of these areas varied considerably between individuals, even the mean length (92 km) was greater than any previously recorded C. ignobilis home range, globally. Findings from this study, including the value of no-take marine protected areas, are of global ecological interest and have implications for local fisheries management. Protecting these vulnerable aggregations is of the utmost importance for the future of this species in southern African waters and elsewhere.
Migratory sharks play a key ecological role through movements within and among marine ecosystems, yet many populations are declining. Addressing the decline is especially challenging for wide-ranging ...species, as they may undertake movements between countries with disparate conservation priorities. To investigate the transboundary migrations of threatened sharks between neighbouring South Africa and Mozambique, we tracked 4 commonly occurring carcharhinid species (bull, blacktip, tiger and grey reef sharks). A total of 102 individuals were fitted with long-life acoustic transmitters and monitored for 4 yr (2018-2022) on an acoustic receiver network of 350 receivers. During this period, 63% of tagged bull sharks (n = 19), 87% of blacktips (n = 13), 94% of tiger (n = 16) and 25% of grey reef sharks (n = 3) undertook transboundary movements. The frequency of mean transboundary movements per year ranged between 1.3 ± 1.5 (SD) for grey reef sharks and 81 ± 35.6 for tiger sharks. Blacktip, bull and tiger sharks all undertook long-distance transboundary migrations ranging from 980 to 2256 km. These data confirm high connectivity between neighbouring countries by threatened sharks undertaking persistent transboundary movements. This study emphasizes the need for collaborative transboundary cooperation between the 2 countries and the alignment of regional management plans and interventions to address declining shark populations in this region of the Western Indian Ocean.
Surveillance of animal movements using electronic tags (i.e., biotelemetry) has emerged as an essential tool for both basic and applied ecological research and monitoring. Advances in animal tracking ...are occurring simultaneously with changes to technology, in an evolving global scientific culture that increasingly promotes data sharing and transparency. However, there is a risk that misuse of biotelemetry data could increase the vulnerability of animals to human disturbance or exploitation. For the most part, telemetry data security is not a danger to animals or their ecosystems, but for some high-risk cases, as with species’ with high economic value or at-risk populations, available knowledge of their movements may promote active disturbance or worse, potential poaching. We suggest that when designing animal tracking studies it is incumbent on scientists to consider the vulnerability of their study animals to risks arising from the implementation of the proposed program, and to take preventative measures.
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BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Blue Economy is a global initiative aimed at using marine resources to create economic viability and environmental sustainability. While successes have been reported, for example, in Europe and ...China, examples of African successes are notably missing. Abject poverty, unemployment and food insecurity are everyday concerns on the African continent; however, its large latitudinal coverage gives rise to extremely biodiverse marine fauna, which could promote socio-economic development of coastal communities through initiatives such as sustainably-managed fisheries. In order to improve sustainability
via
improved management, information on a species and its habitat is needed, particularly how it moves and in which areas it occurs. Acoustic telemetry is a powerful tool used to determine the movements of aquatic animals, the success of which has led to the development of several large-scale networks throughout the globe, including South Africa’s Acoustic Tracking Array Platform. This network, formally in place for the last decade, has now matured, and data are revealing insights into residency, habitat connectivity and transboundary movements of a multitude of animals, with some species having been continually detected for the past 10 years. These data are also actively being incorporated into marine spatial planning efforts, with the aim of protecting threatened and endemic species. Due to knowledge generation, successful benefit-sharing arrangements, and dedication to engage with the public and other stakeholder groups, the ATAP represents a highly successful example of ocean stewardship in Africa.
Medication Desensitization Murray, Taryn S.; Rice, Todd W.; Wheeler, Arthur P. ...
The Annals of pharmacotherapy,
03/2016, Volume:
50, Issue:
3
Journal Article
Peer reviewed
Background: Although its mechanisms are poorly understood, desensitization has been used to induce a temporary state of immune unresponsiveness in patients who have IgE-, non-IgE-, or ...pharmacologically mediated reactions when a drug has no alternatives. Objectives: The purpose of this study was to characterize the outcomes and identify risk factors for reactions during drug desensitization. Methods: A retrospective review of electronic medical records of adult patients undergoing drug desensitization from January 1, 2011, to December 31, 2013, was conducted in 2 intensive care units at a tertiary medical center. We used multivariate analysis to determine if specified risk factors were associated with reacting during the desensitization. Reactions were classified according to the pretest probability prior to desensitization, and then, reactions during desensitization were classified based on the occurrence of cutaneous reactions as follows: successful with no reaction, mild reaction, moderate reaction, or failed. Failure could result from any systemic allergic or cutaneous reaction resulting in procedure termination. The desensitizations were also assessed to determine if the patient required de-escalation secondary to a reaction. Results: A total of 88 desensitizations were performed in 69 patients. Desensitization was completed with no cutaneous reaction in 85% of patients. No baseline characteristic, medication class (P = 0.46), or indication for desensitization (P = 0.59) was associated with having a reaction. Reported histories of urticaria (P < 0.0001) and labored breathing (P = 0.003) during prior exposure were significant in identifying patients who might have a reaction during desensitization. However, neither history of urticaria nor labored breathing was independently associated with having a reaction in multivariate analysis (OR = 0.979, 95% CI = 0.325-2.952, P = 0.970, and OR = 1.626, 95% CI = 0.536-4.931, P = 0.739, respectively). Conclusions: Drug desensitization is safe for patients who have no alternative for therapy. Reported allergy histories of urticaria and labored breathing are both associated with having a reaction during the desensitization process.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
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