Abundances and Distribution

**48**

52:469-479.

*Birds - Challenges and Opportunities for Business, Conservation and Research*

[11] Del Hoyo J, Elliot A, Sargatal J (1992-2013) Handbook of the Birds of the World. Lynx Edicions, Barcelona.

[12] Pigot AL, Sheard C, Miller ET, Bregman TP, Freeman BG, Roll U, Seddon N, Trisos CH, Weeks BC, Tobias

convergence connects morphological form to ecological function in birds. Nat Ecol Evol https://doi.org/10.1038/

JA (2020) Macroevolutionary

[13] Jetz W, Thomas GH, Joy JB, Hartmann K, Redding D, Mooers AO (2014) Distribution and conservation of global evolutionary distinctness in birds. Current Biology 24:1-12.

s41559-019-1070-4

[1] Lei FM, Qu YH, Gan YL, Gebauer A,

microstructure of passerine sparrows in China. J Ornithology 143:205-213.

[2] Baxter S, Cassie ABD (1945) The water repellency of fabrics and a new water repellency test. J Text. Inst

[3] Rijke AM, Jesser WA, Barnard GR, Coertze RD, Bouwman H (2021) The contour feathers of water birds exhibit adaptations to the impact forces of diving, plunging and alighting.

Submitted for publication.

[4] Thomson AL (1964) A new dictionary of birds. Nelson, London

[5] Turner A, Rose C (1989) Swallows and martins of the world. Christopher

[6] Rijke AM, Jesser WA (2011) The water penetration and repellency of feathers revisited. The Condor

[7] Lin CW, Percival P, Gotimer EH (1995) Viscous drag calculations for ship hull geometry. Ninth International Conference on Numerical Methods in Laminar and Turbulent Flow, Atlanta.

[8] Blomberg SP, Garland, Jr. T, Ives AR (2003) Testing for phylogenetic signal in comparative data. Behavioral traits are more labile. Evolution

[9] Collyer ML, Adams DC (2018) RRPP: An R package for fitting linear models to high-dimensional data using residual randomization. Methods in Ecology and

[10] Rijke AM (1970) Wettability and phylogenetic development of feather structure in water birds. J Exp Biol

Kaiser M (2002) The feather

36:T67-T90.

**References**

Helm, London.

133:245-254.

57(4):717-745.

Evolution 9(7):1772-1779.

**51**

**1. Introduction**

**Chapter 4**

**Abstract**

Seabirds of the Benguela

Changes and Challenges

*and Robert J.M. Crawford*

Ecosystem: Utilisation, Long-Term

*Azwianewi B. Makhado, Rodney Braby, Bruce M. Dyer,* 

The Benguela Current is used by c. 82 seabird species, of which seven are endemic to it. Eggs and guano of formerly abundant seabirds were heavily harvested in the 19th and 20th centuries but decreases in seabird populations led to cessation of these industries at islands. Guano is still scraped from platforms. Seabird ecotourism has grown. There were large recent decreases in numbers of African Penguins *Spheniscus demersus*, Cape Gannets *Morus capensis* and Cape *Phalacrocorax capensis* and Bank *P. neglectus* Cormorants and redistributions of these other species away from the centre of the Benguela ecosystem towards its northern or eastern boundaries. In 2020, seabirds endemic to the Benguela ecosystem and albatrosses and petrels migrating into it had high proportions of globally Near Threatened or Threatened species. The primary threat to four Endangered endemic birds was scarcity of forage resources. A Vulnerable endemic damara tern was susceptible to habitat degradation and disturbance. The principal threat to visiting albatrosses and petrels was by-catch mortality. Identification and effective protection of Important Bird Area breeding and marine foraging and aggregation sites, and a suite of complementary measures, are needed to conserve the seabirds and ensure continu-

*Jessica Kemper, Alistair M. McInnes, Desmond Tom* 

ation of their economic and ecosystem benefits into the future.

**Keywords:** Benguela seabirds, conservation status, distributional changes, forage availability, guano, habitat degradation, long-term change, utilisation

The Benguela Current Large Marine Ecosystem (BCLME) in the southeast Atlantic Ocean is one of the world's four major eastern boundary currents, which undergo intense upwelling of cool nutrient-rich waters that support high phytoplankton biomasses and abundant forage fish resources [1]. The forage fishes, in turn, are fed upon by numerous predators, including seabirds [2]. The BCLME ranges from approximately Benguela in southern Angola to Woody Cape at the eastern border of Algoa Bay in southern South Africa, being bounded in the north and east by the warm Angola and Agulhas currents, respectively (**Figure 1**).
