The document discusses the threats facing the endangered Bank Cormorant population in southern Africa and potential implications of its extinction. It outlines several threats driving the species' decline, including oil spills, shifts in prey distribution from overfishing, and increased predation from seals. Conservation efforts discussed include marine protected areas, rehabilitation of oiled birds, population surveys, and attempts to establish an ex situ breeding population to supplement wild numbers. The loss of Bank Cormorants could trigger a trophic cascade affecting other species through reduced control of mesopredators like lobsters and gobies. With continued conservation actions, the document argues it is possible to halt their decline.

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Will we lose the Bank Cormorant Phalacrocorax neglectus by 2100?
How will the loss of this mesopredator affect the marine ecosystem of
the Benguela current?
Introduction
The Bank cormorant (Phalacrocorax neglectus) is a medium sized matt black
seabird that lacks a gular patch, endemic to the Benguela up welling ecosystem
found around southern Africa. A coastal species, it inhabits rocky shore lines and
feeds in coastal kelp beds of sea Bamboo (Ecklonia maxima); the adults are highly
sedentary and rarely venture further than 10km from feeding or breeding grounds
(IUNC 2006). They exhibit benthic feeding strategies diving down to 47.1m feeding
primarily on demersal species such as the Pelagic Goby (Sufflogobius bibarbatus)
and the Cape Rock Lobster(Jasus lalandii) (Ludynia et al 2010). Cape rock lobsters
and Pelagic gobies almost exclusively feed on shellfish and cnidira; predation of
these two species by the cormorants controls the mesopredators’ effects on
mesoconsumers further down the chain, providing a top down control that
mediates ecological interactions. The world population declined by as much as 60%
in the three most recent generations causing the IUNC to classify this species as
Endangered (IUNC 2006); if this rate of decline continues then the species will be
extinct by 2100.
Threats facing cormorants
The total world population was estimated at approximately 2800 breeding pairs in
2006 (IUNC 2006), exceeding the minimal requirements for an effective
population, however, the population is highly fragmented with 80% of the
population breeding on Mercury and Ichaboe, islands in Namibia (Currie et al.
2008). This has made them vulnerable to geographically specific events; this was
highlighted in 2000, when the Treasure oil spill off Robben Island reduced the Bank
cormorant world population by 25% (Rugg et al. 2008). The fragmented population
is also vulnerable to spatial shifts in trophic interactions; Cape fur seals on Ichaboe
Island have experienced a dietary shift towards seabirds, possibly due to reduced
fish stocks, resulting in the predation of 1217 cormorants between 1991 and 2000
(Du Toit et al. 2004). The birds haven’t developed defences for this new threat
and increasing seal numbers may wipe out this integral colony.
Over fishing of Rock Lobster, concentrated around the Northern Cape, has caused
a distributional shift in this important prey species (Crawford et al. 2008). The loss
of prey caused Bank cormorant populations to crash in the over fished areas,
resulting in the extinction of the Lambert’s Bay colony in 1999 (Crawford et al.
2008). These examples, combined with marine pollution, population explosions of
kleptoparasitic kelp Gulls and heat stress from increasing summer temperatures,
have resulted in the dramatic decline of Bank Cormorants over their entire range
(Sherley et al. 2011), however, through the implementations of specific
conservation strategies I believe it’s possible to halt their decline.

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Implications of losing Cormorants
Marine ecosystems consist of complex trophic interactions betweenconsumers and
producers. Cormorants act as benthic mesopredators helping to mediate the
populations of a number of smaller demersal mesopredators including Pelagic
Gobies and Cape Rock lobsters through apostatic selection of more numerous
populations. The reduction in Bank cormorants may affect the populations of
benthic species causing a knock on effect on lower trophic levels, through a
trophic cascade. The reduction of Black tipped reef sharks along the coast of
Eastern U.S.A, caused a population increase in Cow nosed rays which in turn
devastated the local populations of North Carolina bay Scallops, see fig.1 (Heithus
et al. 2008) ; the reduction of Bank cormorants may have a similar effect on the
Benguelan ecosystem. Increasing numbers of mesopredators will in turn reduce the
numbers of producers, affecting primary productivity within the food web and
causing a bottom up control that will
affect the whole ecosystem (Heithus et al.
2008).
Fig.1. Shows the population trends for (a) Black tipped
reef sharks, (b)Cow nosed rays and (c)North carolina bay
scallops, off the coast of Eastern U.S.A between 1970-
2005. Sourced from Heithus et al. 2008
Southern Africa has four species of coastal
Cormorants all of which differ only slightly
in size and diet. The loss of Bank
cormorants may reduce interspecific
competition between similar species and
allow different Phalacrocoracidae species
to fill the niche previously occupied by the
Bank cormorant, mesopredator
replacement. However, this is only
possible in a dynamic food web where
predators are interchangeable, the Bank
cormorants specific roles in the ecosystem
are not yet fully understood, it may be
that the other cormorants smaller size will
stop them from fulfilling the same niche.
Male bank cormorants have been shown to return repeatedly to the same feeding
location, possibly using ocean topography to locate the richest areas (Ludnyia et
al. 2010; Cook et al. 2006). The strong fidelity of feeding grounds may directly
affect the behaviour of prey species in regions of high predation (Heithus et al.
2008). The removal of predators causes a dramatic shift in the prey’s behaviour,
causing them to migrate to previously unsafe areas, altering possible interactions
and changing community dynamics. The reintroduction of wolves into Yellowstone
shows how predators mediate the spatial abundance of prey species; reintroducing

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wolves dramatically affected the distribution of Elk, causing them to shift their
distribution away from areas of high predation, this produced areas of low
herbivory, increasing plant growth rates and aiding in the recovery of Aspen forests
(Beschta & Ripple 2007).
Conservation efforts
Population surveys
Population surveys through ringing, nest observations, GPS and island wide counts
have provided accurate population estimates for each sub population, allowing
conservation strategies for the metapopulation to be devised (Crawford et al.
2001; Bentley 2011; Ludynia et al. 2010). Following a count on Robben Island in
2011 all the subpopulation data was combined to give an estimate of 4000 adult
birds (Bentley 2011). The ringing of 146 chicks on Robben island from 1996-1998,
showed that breeding does not occur until at least three years of age. Observations
of species specific breeding behaviour allow more accurate estimates for possible
breeding population size (Crawford et al. 2001), which is necessary to calculate
future population trends and devise projects to aid population recovery.
Marine reserves
In 2008 the ministry of fisheries in association with WWF and NACOMA declared the
formation of Namibia’s first marine reserve; just south of Walvis Bay, it will be
approximately 30km wide by 400km long incorporating almost a third of Namibia’s
coast line including Mercury and Ichaboe Islands. (Currie et al. 2008). The reserve
is designed to incorporate the most threatened and valuable fisheries as well as
the breeding sites for African penguins, Cape gannets and Bank cormorants, see
Fig.2.
Fig.2 (a) Shows breeding
sites of bank cormorants
along the Southern African
coast:ʘ= colonies with
<100 breeding pairs
=colonies with 100 to
300 breeding pairs,
= Mercury Island.
Sourced from Ludynia et
al. 2010.
(b) Shows the proposed
Marine Protected Area in
turquoise.Sourced from
Currie et al. 2008.
The protection of
spawning and nursery grounds of the Rock lobster is one of the integral roles of the
reserve, helping to stabilise the lobster fisheries, providing sustainable stocks for
(a) (b)

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both human and cormorant consumption (Currie et al. 2008). The combination of
12 marine reserves along the western cape of South Africa and the proposed
Namibian reserve will help stabilise plummeting fish stocks giving seabird numbers,
along the western tip of southern Africa, a chance to rebound.
Guano platform
Rising human populations will continue to put pressure on marine ecosystems and
inevitably only species valuable to humans will be conserved. Namibia has an
annual population growth of 1.4% (Government of Namibia 2011), with the highest
rate of growth concentrated in the capital of Windhoek and in coastal towns. The
majority of Namibia is arid and infertile making the production of crops very
difficult, increasing the demand for cheap effective fertilisers. In the 1930’s Mr
Winter, a local carpenter, built a platform 400m off the coast of Walvis Bay, each
year he increased the size until in 1938 it was over 17,000 square m; his aim was
to harvest guano on an industrial scale. The guano collected from the platform
contains 7% more nitrogen than guano collected from natural sites, as the drier
environment on the platform reduces leaching (Berry 1975). The business soon
became extremely profitable and the platform now provides a breeding site for
thousands of seabirds of up to 6 species. Harvesting the guano at the end of the
breeding season gives the birds sufficient time to breed and stops any possible
conflicts between the guano industry and conservationists. The project has been
copied at multiple sites along the Namibian coast providing cheap efficient
fertilisers for farmers as well as providing protected nesting sites for Africa’s
vulnerable seabirds, including Bank Cormorants. The alignment of anthropogenic
and environmental gain is necessary if in situ conservation strategies are to be a
viable; the continued success of guano
platforms along the Namibian coast may
provide Bank cormorants with the
necessary protection they require to
survive into the future.
SANCCOB rehabilitation
The protection of feeding and breeding
sites for Bank cormorants is vital if the wild
population is to survive, however, direct
action is necessary to combat the increased
human influence on seabirds. In 1968 the
South African Foundation for the
Conservation of Coastal Birds (SANCCOB)
was set up to rehabilitate injured and oiled
coastal birds; since its establishment the table
view site has treated over 85,000 birds,
ranging from African penguins to yellow nosed
Albatross (SANCCOB 2016). Whilst volunteering at SANCCOB during the summer of
2015 I assisted in the rehabilitation of hundreds of seabirds including 1 emaciated
Bank cormorant. The cormorant was placed on a fluid, feeding and physio regime
Fig.3 A volunteer at SANCCOB demonstrates
the technique used to administer fluid therapy
to an African Penguin. Dated 22nd August
2015

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to rehydrate it and improve its overall condition, Fig.3 shows the technique used
to administer fluids. After three weeks of therapy the cormorant was successfully
released at the Stony Point colony; this is a perfect example of the direct impact
that SANCCOB is having on wild cormorant numbers. The constant development of
new management techniques for injured cormorants has resulted in the success
rate of Bank cormorants increasing from 10% to over 30%, see table 1.
The formation of a captive colony
In 2006 SANCCOB launched the Chick Bolstering project aimed to hand rear and
re-release orphaned African Penguins. Research into the success of the fledglings
by Barham et al. showed that the hand reared birds have a higher likelihood of
breeding and an increased fecundity compared to naturally reared individuals
(Barham et al. 2008). The success of this project has significantly increased the
wild populations at Stony Point and Simon’s Bay.
After the success of the project SANCCOB
collaborated with Living Coasts in Torquay to
attempt to produce the world’s first captive
breeding population of Bank Cormorants,
utilising hand rearing techniques acquired in the
chick bolstering project. Living Coasts has
housed 2 male Bank Cormorants since 2003, see
fig.5 (Rugg et al.2008); the pair were orphaned
due to building work on Robben Island and were
sent to Living Coasts in 2003 as SANCCOB did
not have the space to permanently house more
birds. In 2009 12 cormorant eggs were sent to
Living Coasts in the hope that some females
could be reared and paired with the existing
males.
Admitted
2001/2 2003 2004 2005 2006 2007 2008 2009 2010
8 18 6 7 3 1 3 8 3
Died
2001/2 2003 2004 2005 2006 2007 2008 2009 2010
7 14 4 7 2 1 2 3 2
Released
2001/2 2003 2004 2005 2006 2007 2008 2009 2010
1 3 2 0 1 0 1 4 1
Success rates
2001/2 2003 2004 2005 2006 2007 2008 2009 2010
10% 16.6% 33.3% 0% 33.3% 0% 33.3% 50% 33.3%
Fig.5 Amanzi, one the two male Bank Cormorants
housed at Living Coasts,Torquay, Devon. Dated
December 11th 2013.
Table 1. The numbers of Bank cormorants admitted to SANCCOB, died at SANCCOB and released back
into the wild, 2001-2010. The success rates were calculated by dividing the admittance by the number
successfully released. Sourced from a patient log book* at SANCCOB’s Table view site, in August 2015.

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The avicultural team at Living Coasts, headed by Lowis Rowell, developed the
initial husbandry protocols by combing techniques used by SANCCOB and by
California’s Sea world team in the rearing of the closely related Blue eyed shag
(Henry et al. 2011). This initial attempt was however unsuccessful with all but one
of the chicks dying at 12 days (highlighting a vitamin deficiency in the bird’s diet).
In light of this it was decided that the formation of an ex situ population was
currently not feasible due to the low success rate and huge cost of the project, the
cost of a second attempt was calculated at £3,776 (Rugg et al. 2008). Instead,
efforts have been concentrated on the formation of an in situ breeding colony at
SANCCOB’s Table view site.
In the summer of 2015 SANCCOB and
Lois Rowell collected a further 10 eggs
from Robben Island and attempted to
hand rear the chicks on a new formula,
which replaced the oil rich fish
previously used, with smelt and pinkies(
day old mice) (Edmunds et al. 2011).
This second attempt successfully reared
two female cormorants, see fig.6, and
provided valuable knowledge on the
necessary techniques required to rear
this species. SANCCOB is currently raising
funds to expand the Table view site to
incorporate a specially designed
enclosure that will house a colony of
10+ Bank cormorants, with hopes of
producing a self-sustaining captive
population that can be used to supplement wild colonies. The project is still in its
infancy and requires a lot of funding before the results can be evaluated.
Reintroduction projects, whilst successful, are extremely expensive to fund; the
Californian condor reintroduction program cost approximately $35 million (U.S.
Fish and Wildlife 2016) and still hasn’t managed to produce a self-sustaining wild
population. If sufficient funds can be raised to produce a captive population and
efficient management of the genetics is implemented this project could mirror the
penguin project and drastically increase Cormorant colonies throughout their
range.
Conclusion
The decline of predatory species such as cormorants highlights ecological issues
present along the coastlines of some of the most developed countries in Africa.
Without conservation action Africa’s famous skeleton coastline will not only lose
its endemic Bank cormorant but also iconic species such as Great White Sharks,
African Penguins and Southern Right whales. However, the array of current and
future projects aimed at saving not only Bank cormorants but the ecosystem as a
whole suggests that this ecological community is likely to survive into the future
Fig.6 One of the two successfully hand reared Bank
Cormorants in 2015, drying after a swim in a temporary
enclosure. Dated 18th August 2015.

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and I predict that there will be Bank cormorants roosting along the coast lines of
southern Africa in the year 2100.
Bibliography
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Boltona, D.A., Dyera, B.M. & Upfolda, L. (2008). The efficacy of hand-rearing
penguin chicks: evidence from African Penguins (Spheniscus demersus) orphaned in
the Treasure oil spill in 2000. Bird Conservation International.18:144-152
Bentley, D. (2011) Island count of Bank Cormorants on Robben Island.
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IUNC Red list of threatened species.2015. Bank Cormorant.
http://www.iucnredlist.org/details/full/22696766/0. Accessed 2/3/2016
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Rugg, C., Hayes, E. & Rowell, L. (2008). Letter addressed to AHIT, proposing the
collecting of Bank cormorant eggs. (Letter)
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bolstering-project. Accessed 2/3/2016.
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and heat limit the nest success of Bank Cormorants: implications of future climate
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*ICU log books from 2001-2010, for SANCCOB’s Table view site. Updated by the
resident rehabilitator daily. Information in the book includes the number, species,
sex, injury and location of all newly admitted birds.
N.B. Figures 3, 4 and 5 are pictures I have taken whilst volunteering at Living
Coasts and SANCCOB.