Conserving Benguela endemic seabirds

All three seabirds endemic to the Benguela upwelling ecosystem that rely on anchovies and sardines are threatened by local reductions in the availability of their preferred prey. Small pelagic fish abundance has decreased off the southern African west coast, where fishing effort is concentrated, and most seabird breeding islands are located. As a result, it is crucial to understand the foraging behaviour of breeding seabirds and how their populations respond to changes in fish abundance and distribution.

The lack of spatial management of the fishery for small pelagic fish has resulted in local over-exploitation of sardines and anchovy. Throughout the last decade, the small pelagics fishery has failed to meet its quota almost every year, indicating a paucity of these fish. African Penguins Spheniscus demersus, Cape Cormorants Phalacrocorax capensis and Cape Gannets Morus capensis all depend largely on these same fish, and all three species are now listed as Endangered. Understanding the drivers behind such population changes is essential to mitigate these declines. This is a large, multi-faceted programme with a large number of participants from a diverse array of institutions.

Activities in 2022

• The experimental closure of commercial fishing for small pelagic fish around key penguin breeding islands has stopped since 2021. A Task Team assigned by the Minister of Forestry, Fishery and the Environment proposed closures based on GPS data from foraging penguins and fishing catches around the six main breeding colonies. However, this was rejected by the fishing companies. As a consequence, no African Penguin colony was protected from purse-seine fishing in 2022. The Department called on the Consultative Advisory Forum (CAF), constituted of Fishery representatives, Fishery scientists and one scientist from SANBI, to advise on a way forward. Their proposal significantly reduced the size of the fishing exclusions and was rejected by both fishing industries and environmentalists. Thanks in part to public pressure, temporary fishing exclusion areas were declared on 1 September, and will remain in place until an external scientific panel has been constituted to review the various proposals. 
• Long-term monitoring of African Penguins continued in Algoa Bay, with tracking data collected on Bird Island in May 2022, as well as measures of chick condition and breeding success. Tracking data can no longer be obtained from St Croix due to the small numbers of penguins. From July 2022 SANParks recruited six seabird monitors to assist with collecting data on penguin population size and breeding success.
• The penguin weighbridge on St Croix has not been functioning but a new weighbridge was installed on Bird Island in September 2022. By using weighbridges linked to transponder readers we can monitor penguin fish catches in relation to foraging effort with minimal disturbance to the birds. Eleanor Weideman has been appointed by BirdLife South Africa to work on these data towards her PhD.
• Lorien Pichegru deployed two static hydrophones to measure underwater noise levels in Algoa Bay, one at St Croix Island and one at Bird Island, and also recorded noise levels in the vicinity of ships being refueled in Algoa Bay. 
• Lorien and Shaun Welman (NMU) published an article in Bird Conservation International using automated cameras to assess the thermoregulatory behaviour of penguins in natural and artificial nests equipped with temperature and humidity recorders. African Penguins breeding in surface nests exposed to the sun started panting at air temperatures as low as 22°C, compared to 25°C in shaded nests. However, the latest artificial nests with a double ceramic layer buffer environmental conditions even better than natural guano burrows. The research will be extended in collaboration with Two Ocean Aquarium to test hyperthermia thresholds in eggs. Further research on heat stress in African penguins is also being extended to other colonies in collaboration with Dallas Zoo and the Dyer Island Conservation Trust.
• NMU MSc student Praxedes Rukuni, supervised by Lorien, Giannina Passuni and Shaun Deyzel (SAEON), graduated in 2022. Her thesis focused on food web stability in Algoa Bay using meso-zooplankton functional diversity metrics. She found that the anchovies targeted by penguins breeding on Bird Island fed mostly on large crustaceans, whereas those targeted by penguins from St Croix Island fed on a wider range of smaller, less energetically beneficial prey, reflecting the less productive waters close to St Croix. 
• NMU MSc student Catherine Currin, supervised by Lorien and Andre Ganswindt, also graduated in 2022. In her thesis, she used a newly-designed electronic heart rate recorder to compare stress levels in captive penguins. Although she could only use a small proportion of the data recorded by the eggs, she showed that encounters with conspecifics including interactions with a mate elicited much higher heart-rate responses than the presence of humans in their enclosures. These results confirm that African Penguins can get habituated to the presence of humans. 
• NMU MSc student Victoria Stockdale, supervised by Lorien and Mandy Lombard continued to develop a system dynamics model to simulate the relationships between penguin foraging and breeding success and the purse-seine fishing industry over time, in order to recommend dynamic fishery closures that deliver maximum benefits for penguins while minimising the impact on the fishing industry.
• Tegan Carpenter-Kling deployed trackers on pre-moult juvenile African penguins and post-breeding Cape Gannets.
• David Grémillet and Lorien Pichegru continued their long-term study tracking the foraging ranges of Cape Gannets breeding on Malgas Island, which was initiated in 2002. SANParks continues to manage the Kelp Gull population on the island, greatly decreasing predation on eggs and small chicks. 
• Pierre Pistorius and Newi Makhado continued monitoring the Cape Gannet population breeding on Bird Island, Algoa Bay. Andrea Thiebault, a former NMU post-doc, is using historic tracking data to compare the various methods used to infer where seabirds forage.
• Julien Collet joined NMU as a post-doc and also worked on the long-term tracking data collected from gannets. Using tracking data from multiple foraging trips collected from the same individuals, Julien demonstrated, for the first time in Cape gannets, that individuals tend to return to previously explored foraging areas. These results are being prepared for publication. 
• Zanri Strydom submitted her PhD (supervised by Herve Fritz, Jan Venter, Lorien Pichegru and David Grémillet) on the foraging behaviour of Cape Gannets in relation to their age and experience. Although she found no pattern of senescence in the behaviour of adult Cape Gannets, older females had higher foraging effort than younger females and males.
• In early 2023, MSc student Kezia Bowmaker-Falconer will submit her MSc thesis on the diet of African Penguins and Cape Gannets in Algoa Bay using DNA metabarcoding of faeces. She presented her results at the South African Marine Science Symposium in Durban in June 2022.
• Nosipho Gumede finalised her MSc, supervised by Newi Makhado, Mduduzi Seakamela and Peter Ryan, on long-term variation in the diet of Cape Fur Seals Arctocephalus pusillus, and the potential for competition with fisheries and seabirds. 
• CB MSc student Sara Forsberg analysed a 30-year study of fur seal entanglement in Cape Town harbour for her research project.

Highlights

• Lorien Pichegru obtained a C1 NRF-rating, and remains Acting Director of the Coastal and Marine Research Institute at NMU. 
• Nine papers were published in peer-reviewed journals during 2022.
• Lorien Pichegru led on a paper on the possible role of shipping noise on the rapid decline in African Penguins in Algoa Bay, which was presented at five conferences and attracted considerable media attention after it was published in Science of the Total Environment. It resulted in Transnet, the national Port Authority, requesting a meeting with the co-authors to explore how noise pollution could be reduced in Algoa Bay. A follow-up meeting will take place in 2023. 
• Lorien and David Grémillet contributed to a paper in Communication Biology led by Nicolas Courbin on the ‘Seascape of fear’ hypothesis. They suggest that Cape Gannets’ foraging strategies attempt to avoid both fishing vessels and Cape Fur Seals.
• Tegan Carpenter-Kling published a large collaborative paper in PLoS One reporting pre- and post-moult distribution of African Penguins from various colonies around South Africa. 
• Former PhD student, Katharina Reusch, published two papers from her thesis, one on the foraging ecology of Kelp Gulls Larus dominicanus and one on their health status and parasite loads. Her last paper on Kelp Gull diet is under review.
• NMU MSc student Kezia Bowmaker-Falconer published her Honours project assessing the sexual and individual signatures encoded in Cape Gannet calls in Ostrich. 
• Lorien Pichegru started a study commissioned by DFFE assessing the efficacy of conservation interventions listed in the first African Penguin Biodiversity Management Plan gazetted in 2013. The study is due in July 2023.

Key co-supporters
BirdLife International; BirdLife South Africa; DSI-NRF CoE grant, Marine and Coastal Research Grant (NRF).

Research team 2022
Prof. Pierre Pistorius (NMU)
Prof. Res Altwegg (SEEC, UCT)
Prof. Peter Ryan (FIAO, UCT)
A/Prof. Lorien Pichegru (NMU)
Dr Tegan Carpenter-Kling (BLSA)
Dr Maëlle Connan (Mandela Uni.)
Dr Rob Crawford (Oceans & Coasts, DFFE)
Dr David Grémillet (FIAO, UCT and CNRS)
Dr Katta Ludynia (SANCCOB)
Dr Azwianewi Makhado (Oceans & Coasts, DFFE)
Dr Alistair McInnes (BLSA)
Dr Florian Orgeret (NMU Post-doc)
Dr Richard Sherley (U. Bristol)
Dr Andrea Thiebault (Marie Curie Post-doc)

Students: Zanri Strydom (PhD, NMU); Catherine Currin (MSc, NMU); Nosipho Gumede (MSc, UCT); Praxedes Rukini (MSc, NMU); Victoria Stockdale (MSc, NMU); Kezia Bowmaker-Falconer (MSc, NMU); Sara Forsberg (CB MSc, UCT).