Guano - the white gold of Peru

Guanay cormorants at Punta San Juan (© Jean Pichon / Mundo Azul)

Guano is bird droppings. The word guano derived from huanu a native Quechua language word for manure. It is a natural fertilizer, rich in nitrogen, phosphorus and potasium, which has been exploited already by pre-inca cultures. Millions of marine birds have left layers of bird droppings covering the rocky islands and cliffs off the Peruvian coast. Historically, these layers reached a thickness of up to fifty meters. 170 years ago the world became aware of the guano and demand increased explosively causing an economic boom.

Guano is still harvested. There are about 26 islands and 13 headlands that are forming the so called guano system and are exploited for their guano every 5 to 7 years during the nonbreeding season depending on the amount of guano and number of birds in the colonies. This guano is used in crops in Peru, and small amounts are exported to the United States and Europe.

There are many different marine birds breeding on the islands and headlands of the guano system. However there are three species being the most important guano birds because of their sheer numbers:

 

Threats

Nowadays, however, the guano birds are in grave danger. Of the 35 to 40 million guano birds nesting off the Peruvian coast, merely 1.8 million are left. Within the last 60 years the total population of guano birds was reduced by 95 percent.

Guano birds are threatened by the deadly combination of three factors:

The El Niño phenomenon has always caused strong mortalities in the guano bird population. The black arrows in the graphic, mark strong El Niño events and their impact on the bird populations. As can be seen in the first event registered in the graphics, the devastating short term effect of El Niño previously had not been a major problem for the birds. With the return of their main prey, sardines and anchovies, the guano population could recover within a few years.

However, by the 1950's a new industry started in Peru, the industrial fishery for Peruvian anchovy replaced the birds and competed for their food, replacing the guano for fish meal as a main profit income. Even though Guanay Cormorants Leucocarbo bougainvillii and Peruvian Boobies Sula variegata feed on a wide range of fish resources, they show preference for Peruvian Anchovy Engraulis ringens. Guano-producing seabird population decreased as the catches of Peruvian anchovy increased. With annual captures of up to 8 million tons of anchovies and a fleet overcapacity estimated between 30 to 100 %, there is simply not enough food left for the birds.

Population increase from 1953 to 1971 was limited by the quick development of the industrial fishery, and was drastically reduced due to El Niño events (ENSO) occurred in 1957/58 and 1965. Over-fishing and ENSO 1972/73 collapsed anchovy stocks and caused a high guano-birds mortality. The following population increase was very slow because of the capture levels observed from 1972 to 1982. ENSO 1982/83 occurred during the breeding season and caused total nesting areas abandonment and the mortality of 58% of the population.

By 1996, Guanay Cormorant population had decreased to an estimated 3.7 millions of birds, Peruvian Boobies to 2.6 millions and Peruvian Pelicans to 400 thousand birds in comparrison to the beginning of the 20th century.

As a consequence of El Niño event, guano- producing seabird populations decreased further during 1997. Changes in the marine environment near the colonies reduced food availability, Peruvian anchovies moved to deeper waters or migrated southward. ENSO 1997-98 started after most cormorants and boobies finished the breeding season; therefore, most guano-producing seabirds were ready to migrate southward searching for food. In contrast to other El Niño events, few birds were found dead along the coast.

Nowadays, guano birds live in a kind of artificial El Niño situation, where acute food shortage maintains population size at a low. At this point, further food shortage caused by natural El Niños becomes fatal to the birds survival.

Cadaver of illegally killed guano bird, confiscated Callao food markets (© Stefan Austermühle / Mundo Azul)

Additionally, guano birds are illegally killed by artisan fishermen for human consumption, purely a poverty caused problem. The birds, from pelicans to penguins are sold on the markets to the poorest levels of society. In June 2003, an artisan fishing boat was caught by the Peruvian navy, carrying 2,000 dead guano birds on board destined to be sold on the meat markets. In police operations, based on information from under-cover investigations by Mundo Azul, illegal dealers of guano bird meat could be caught in the markets of the city of Callao.

The biggest part of guano birds nowadays nests on the 35 guano islands and cliffs under the management of the state-owned guano production company Proabonus, a company that runs nearly without generating profits as the few birds left do not produce enough guano anymore. A formerly important export product, that could generate good profits on the market for natural fertilizers, being increasingly demanded by the organic agriculture, has been destroyed by the fish meal industry.

The guano island system (23 islands and 10 cliffs) was created more than 100 years ago in order to give strict protection to the guano birds. Nowadays, the guano islands are also the last refuge for a number of other endangered marine species. They are the breeding ground for 72 percent of the South American fur seal (Arctocephalus australis), 84.4% of the Southern sea lions (Otaria byronia), 60% of the Humboldt penguins (Spheniscus humboldti), and, most important, the entire population of the endemic and highly endangered Peruvian diving petrel (Pelecanoides garnottii).

Humboldt penguins (© Stefan Austermühle / Mundo Azul)

Even though the islands are officially protected by law, some of them already have been invaded by artisan fishermen, fishing in front of them or killing birds. Aquaculture projects also have been installed on and around the islands and cause further human presence on the islands.

Mundo Azul initiated together with other Peruvian and international NGOs an initiative to declare the guano islands, "officially protected areas" and integrate them as a National Reserve in the governmental system of protected areas (SINANPE). Up to now, the proposal, being officially adopted by the National Institute for Natural Resources (INRENA), got stuck in the bureaucracy because of the special interests of the fishing industry and the mining industry as well as a lack of support from governmental institutions from the fishing sector.

Peruvian boobies nesting in coastal cliff (© Stefan Austermühle / Mundo Azul)

What needs to be done in order to protect the guano birds?

• The guano islands need to be declared a National Reserve.
• The fish meal fisheries need to be reduced significantly.
• The government needs to create economic incentives to convert the fish meal fleet into a fleet for human consumption fisheries
• Law enforcement has to be improved in order to avoid illegal hunting of guano birds.

Guano boom

About 170 years ago the world became aware of the guano and demand increased explosively causing an economic boom. Intoxicated by prosperity, the Peruvian Government pursued a single goal: Dig up the guano as fast as possible; ship it to United States, Europe, and other part of the world; count the profits. No thought was given to the welfare of the birds that produce guano; no thought for the enormous time required to amass deep, rich deposits. In the third quarter of the 19th century alone, the peak of mass exportation, Peru shipped an estimated 20,000,000 tons, worth two billion dollars. A few decades later, with guano reserves depleted, Peru faced agricultural disaster, for the rich fertilizer is absolutely essential, together with irrigation, to support its farms. The fresh guano crop dipped in 1909-1910 to 48,809 tons, a minute fraction of the country's own yearly need. In 1908 the Peruvian Government created the Guano Administration Company that worked hard to recover guano-producing seabird populations, by constructing walls around the mainland breeding colonies that protected the birds from natural predators. With this and other measures they managed to increase the guano bird population in Peru to about 40 million in the 1930s.

The Guanay Cormorant

Scientific name: Phalacrocorax bougainvillii
Peruvian name: Guanay

Guanay (© Jean Pichon / Mundo Azul)

The Guanay Cormorant is an endemic bird of the Humboldt Current area whose distribution is restricted to the west coast of South America from Foca Island (5°S) in Peru to Mocha Island (38°S) in Chile. It is the most abundant seabird species that inhabits the Peruvian Coast and the most important guano-producing seabird. During the mid-twentieth century, Guanay Cormorant population reached 20 million birds. Increasing catches of Peruvian anchovy by the industrial fishery and the ENSO events limited the food availability for these birds and contributed to reduce the population. After ENSO 1982-83, less than 0.3 million of birds were left. Guanay Cormorant population was recovering since 1984 and reached in 1996 more than 3.7 million birds. ENSO 1997-98 started after cormorants breeding season finished and caused a southward migration of birds. The number of Guanay Cormorants in Peru decreased through 1997 in about 99.4% due to migration, few birds were found dead along the coast.

Guanay Cormorant colonies during nonbreeding periods are often crowded with birds and more than 15 individuals can be seen in a single square meter. During breeding season 3.5 nests are established in each square meter, thereby decreasing bird density.

The breeding season occurs during the austral summer (December to March), some pairs may attempt to breed a second time in a year depending on food availability. Guanay Cormorants lay two or three egg clutches. Eggs are incubated during approximately 4 to 5 weeks, both adults share nest attendance. The rearing period lasts about 3 months. Breeding success depends on food availability and is related to colony location and timing of breeding.

 

Guanay Cormorants feed on more than 69 different fish species, but show a strong preference for Peruvian Anchovies Engraulis ringens, the most abundant pelagic fish in the Peruvian Upwelling System. Other important fishes in the diet are Normanichthys crockery, Odonthestes regia and Anchoa nasus. Remainig species contribute with less than 6% of the ingested food.

The Peruvian Booby (Sula variegata)

Peruvian name: Piquero peruano

The Peruvian Booby is an endemic bird of the Humboldt Current area whose distribution is restricted to the west coast of South America from Punta Pariñas (4.6°S) in Peru to Concepcion in Chile. It is the second most abundant seabird species that inhabits the Peruvian Coast and the second most important guano-producing seabird. During the mid-twentieth century, Peruvian Booby population reached 3 million birds. After ENSO 1982-83, less than 0.2 million birds were left. Peruvian Booby population was recovering since 1984 and reached in 1996 more than 2.6 million birds. ENSO 1997-98 started after most boobies finished the breeding season and caused a southward migration of birds. The number of Peruvian Boobies in Peru decreased through 1997 in about 87.1% due to this reason, few birds were found dead along the coast.

Piquero común (© Jean Pichon/ Mundo Azul)

Peruvian Boobies breed throughout the year. Main breeding season occurs during the austral spring-summer period (September to March) and most pairs may attempt to breed for a second time during the year depending on food availability. Peruvian Boobies clutch size varies from one to four eggs, but clutches of two or three eggs, pale blue in color, are usually found.

Eggs are incubated during approximately 4 to 5 weeks; both adults share the nest attendance. The rearing period lasts about 3 months. Breeding success depends on food availability and is related to colony location, colony size and timing of breeding.

Peruvian Boobies feed on more than 18 different fish species and one squid species, showing a strong preference for Peruvian Anchovies Engraulis ringens, the most abundant pelagic fish in the Peruvian Upwelling System. Other important fishes in the diet are Odonthestes regia, Scomberesox saurus and Sardinops sagax. Remainig species contributed with less than 4% of the ingested food. Anchovy consumption by Peruvian Boobies was higher from spring to autumn than in winter, as during winter anchovy schools may reach twice the depth of spring, making this prey less available for boobies.

The Peruvian Pelican (Pelecanus thagus)

Peruvian name: Pelícano peruano, Alcatraz

Pelicano (© Stefan Austermühle / Mundo Azul)

The Peruvian Pelican is an endemic bird of the Humboldt Current area whose distribution is restricted to the west coast of South America from Lobos de Tierra Island (6°S) in Peru to Pupuya Islet (33.5°S) in Chile. It is the third most important guano- producing seabird in Peru. During 1996, Peruvian Pelican population reached 400 thousand birds. ENSO 1997-98 caused a southward migration, decreasing population numbers through 1997 in about 99.4%, few birds were found dead along the coast.

Peruvian Pelicans main breeding season occurs during the austral spring-summer period (September to March). Clutch size varies from one to eight eggs, but clutches of two or three eggs are usually found. Eggs are incubated during approximately 4 to 5 weeks, both adults share the nest attendance. The rearing period lasts about 3 months. Peruvian Pelicans feed on several fish species, showing a strong preference for Peruvian Anchovies Engraulis ringens, the most abundant pelagic fish in the Peruvian Upwelling System. Other important fish in the diet are Sardinops sagax, Trachurus murphyi and Scomberesox saurus.