**2. Utilisation**

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

*Thalassarche carteri* Indian Yellow-nosed

*Thalassarche chlororhynchos* Atlantic Yellow-nosed

*Thalasseus b. bergii* Greater Crested (Swift)

Albatross

Albatross

Tern

*has recently been reclassified as the West African Crested Tern* Thalasseus albididorsalis*.*

*Thalassarche cauta* Shy Albatross Near Threatened Unknown

*Thalassarche chrysostoma* Grey-headed Albatross Endangered Decreasing *Thalassarche melanophrys* Black-browed Albatross Least Concern Increasing *Thalassarche salvini* Salvin's Albatross Vulnerable Unknown

*Thalasseus maximus* Royal Tern Least Concern Stable *Thalasseus sandvicensis* Sandwich Tern Least Concern Stable *Xema (Larus) sabini* Sabine's Gull Least Concern Stable

*The conservation status of seabirds that occur in the BCLME (rare vagrants have been excluded). Where known, the recent global population trend is indicated [4]. Information is sorted on genus and then species. Grey shading indicates species or races that breed only in the BCLME. The Royal Tern occurring in the BCLME* 

**Species Common name IUCN status Population** 

*Phalacrocorax neglectus* Bank Cormorant Endangered Decreasing *Phalaropus fulicarius* Red (Grey) Phalarope Least Concern Unknown *Phalaropus lobatus* Red-necked Phalarope Least Concern Decreasing *Phoebetria fusca* Sooty Albatross Endangered Decreasing *Phoebetria palpebrata* Light-mantled Albatross Near Threatened Decreasing *Procellaria aequinoctialis* White-chinned Petrel Vulnerable Decreasing *Procellaria cinerea* Grey Petrel Near Threatened Decreasing *Procellaria conspicillata* Spectacled Petrel Vulnerable Increasing *Pterodroma incerta* Atlantic Petrel Endangered Decreasing *Pterodroma macroptera* Great-winged Petrel Least Concern Decreasing *Pterodroma mollis* Soft-plumaged Petrel Least Concern Stable *Puffinus assimilis* Little Shearwater Least Concern Decreasing *Puffinus puffinus* Manx Shearwater Least Concern Unknown *Spheniscus demersus* African Penguin Endangered Decreasing *Stercorarius longicaudus* Long-tailed Jaeger Least Concern Stable *Stercorarius parasiticus* Arctic (Parasitic) Jaeger Least Concern Stable *Stercorarius pomarinus* Pomarine Jaeger Least Concern Stable *Sterna albifrons* Little Tern Least Concern Decreasing *Sterna dougallii* Roseate Tern Least Concern Unknown *Sterna hirundo* Common Tern Least Concern Unknown *Sterna paradisaea* Arctic Tern Least Concern Decreasing *Sterna vittata* Antarctic Tern Least Concern Unknown *Sternula balaenarum* Damara Tern Vulnerable Decreasing *Sula leucogaster* Brown Booby Least Concern Decreasing *Sula sula* Red-footed Booby Least Concern Decreasing

**trend**

Endangered Decreasing

Endangered Decreasing

Least Concern Stable

**54**

**Table 1.**

#### **2.1 Penguin eggs**

From the late 1400s, African Penguins *Spheniscus demersus* and other seabirds in the BCLME were caught as food by early explorers, as fuel to supply ship boilers and to be rendered down for their fat [5, 6]. However, the primary attraction of African Penguins was their eggs. Collection of these on a large scale may have begun as early as 1652 [7]. Details of numbers of eggs collected at different breeding localities are available for each year from 1871–1967 (after which collections ceased) with gaps from 1879–1890, 1894–1896 and in 1904 and 1914 [7].

Annual collections averaged c. 192,000 eggs from 1871–1878, c. 537,000 eggs from 1891–1931 and c. 76,000 eggs from 1935–1967 (**Figure 2**). The overall harvest for the 80 years between 1871 and 1967 for which records were kept was c. 23.4 million eggs, with a maximum of 801,500 eggs in 1899. About 99% of the eggs were taken off western South Africa (84% from Dassen Island), with small proportions coming from southern Namibia (< 1%) and southwestern South Africa (c. 1%). Although ease of access to colonies and of gathering eggs would have influenced localities selected for collections, their geographical distribution approximated that of African Penguins at the time. In the early 1900s, Dassen Island off western South Africa was the largest colony holding an estimated 0.57–0.93 million breeding pairs between 1910 and 1930 [8, 9]. In 1956, no African Penguins bred in Angola or northern Namibia. The proportions then breeding in central and southern Namibia and in western, southwestern and southern South Africa were 5%, 25%, 62%, 3% and 5%, respectively [10].

**Figure 2.** *Trends in total collections of African Penguin eggs and seabird guano in the BCLME, 1871–1999.*

At Dassen Island, c. 48% of penguin eggs produced in the early 20th century were collected; this was unsustainable and led to an estimated decrease in the number of penguins there aged two years or older, from c. 1.45 million in 2010 to c. 0.22 million in 1956 and 0.14 million in 1967 [8].

### **2.2 Guano**

In the 1840s, after the value of guano as an agricultural fertilizer became known, accumulated deposits of seabird guano were stripped from many southern African islands [11]. Then, from the late 1800s until the mid-1980s or early 1990s, fresh deposits of seabird guano were regularly collected at a number of islands off Namibia and South Africa. At Ichaboe Island in central Namibia sporadic guano extraction persisted until 2016. From 1896, annual records of quantities removed from different islands were maintained [12]. Most of the guano extracted from the islands was produced by Cape Gannets *Morus capensis* and Cape Cormorants *Phalacrocorax capensis*. Phosphatic sand was at times removed from African Penguin breeding areas at Dassen Island to mix with guano or to spread over breeding areas of Cape Gannets, which build their nests from guano [13]. In southern Africa, the African Penguin, Cape Gannet and Cape Cormorant became known as the 'guano-producing' seabirds, although other cormorants and Great White Pelicans *Pelecanus onocrotalus* would have contributed small amounts to guano depositions at some localities. Between 1930 and 1971 platforms were constructed by private entrepreneurs to collect guano at Bird Rock, Swakopmund and Cape Cross on the northern Namibian coast, which was mainly produced by Cape Cormorants [14]. Annual records of quantities taken from each platform were maintained [15]. Between 1900 and 1999, an average of c. 5,700 t of seabird guano (after subtraction of additions of phosphatic sand) was extracted annually in the BCLME, with a maximum of c. 9,600 t and a minimum of c. 1,500 t (**Figure 2**).

Guano extraction sometimes displaced or caused disturbance to seabirds, reducing breeding success [16]. It also created hollows on some islands, allowing rain to accumulate, which on occasion flooded nests of some seabird species and also reduced breeding success [17].

#### **2.3 Tourism**

Seabird tourism is a rapidly expanding industry in the BCLME. In South Africa, Boulders at Simon's Town, Stony Point at Betty's Bay and Robben Island provide opportunities for the public to observe African Penguins and other seabirds in their natural habitat and have become popular tourist destinations that generate socio-economic gains through gate fees, provision of jobs and benefits to surrounding areas [18]. For example, Boulders provided 885 jobs directly associated with its penguin colony and expenditure related to the colony was approximately ZAR 311 million [19]. It contributed to the overall branding of Cape Town as a popular destination for international visitors [18]. The Stony Point penguin colony received an average of 77,500 visitors p. a. from 2010–2019 [20]. The Cape Gannet colony at Lambert's Bay is an important source of revenue for that community [20]. Land tours to view breeding and roosting seabirds operate in Namibia, e.g. [21]. Boatbased seabird viewing operates out of several southern African ports, including around the largest African Penguin colony at St Croix Island [20].

It was estimated that seabird tourism contributed c. ZAR 500 million to the South African economy in 2020 [20].

**57**

**Figure 3.**

*Seabirds of the Benguela Ecosystem: Utilisation, Long-Term Changes and Challenges*

*Average collections of seabird guano in six regions of the BCLME over 11 decades, 1890s–1990s.*

Production of guano at the platforms in northern Namibia commenced in the 1930s when the average yield was c. 450 t p.a.; it then increased to a peak of c. 3,350 t in the 1980s before a decrease in the 1990s. By contrast, yields in central and southern Namibia and western South Africa peaked in the 1920s at c. 3,500 t, 1,900 t and 2,300 t p.a., respectively, and then decreased. In southwestern South Africa, production peaked at c. 400 t p.a. in the 1910s and then decreased. In southern South Africa it increased from c. 120 t p.a. in the 1890s to an average of c. 340 t p.a. between the 1920s and 1980s (**Figure 3**). Hence, there were long-term increases in guano yields in northern Namibia and southern South Africa but

**3. Long-term changes in distribution and abundance**

*DOI: http://dx.doi.org/10.5772/intechopen.96326*

**3.1 Guano**

*Seabirds of the Benguela Ecosystem: Utilisation, Long-Term Changes and Challenges DOI: http://dx.doi.org/10.5772/intechopen.96326*
