- Robin des Bois - http://www.robindesbois.org/en -

Fish Eat Whales

The 63rd annual meeting of the International Whaling Commission (IWC) will take place from July 11th to 14th on the Channel Island Jersey.

Pro-whaling countries often state that whales must be culled to avoid competition with human fisheries. Japanese “scientific” documents show images of whales’ stomachs overflowing with small pelagic fish. According to Robin des Bois a defender of whales, one must continue to demonstrate that whales have positive effects not only on the world’s marine ecosystem but on all ecosystems. We cannot accuse whales of taking all and giving nothing to the oceans, while it is Man who takes all and gives nothing but pollution and increasing disturbances.

1 – Tillers of the Sea

Certain whale species such as the Gray whales, Beaked whales, Right whales and Humpback whales are believed to brush across the bottom of the ocean when foraging for prey such as worms, crustaceans and sand lance. This type of excavation and stirring up of the ocean floor is a positive contribution which enhances biological productivity(1). While it may appear that whales turn the ocean floor into a battleground, bottom-dwelling activities are in fact a type of sustainable management(2). Through tilling, creating pits and gouges, while obtaining its feed, the Gray whale expels mouthfuls of sediments either on the ocean floor or brings it up to the surface. This movement of debris releases buried sediments and nutrients while carrying out a natural recycling-cleaning and sowing of the seafloor.

The excavations can be a couple of meters in both length and width and are colonised by pioneer benthic species. Then, the pits aggregate organic debris from shells, seaweeds or zooplankton and are in the same time used as a cover and feeding area by new benthic communities.

The cultivated zones attract micro-marine life which can be between 2 to 30 times denser in the “tilled” areas than in the non-excavated sediment (3). This eventually enhances the habitat where the whales will return in the following “farming season”. The resuspension of sediments and microorganisms thus sustains resources through the cyclic renewal of benthic biodiversity.

2 – The best fertilisers in the world

While whales forage at depths, respiration permanently links whales to the surface and the mammals return to the surface to defecate – with species such as Right whales and fin whales producing around 15 kilograms of faeces per day(4). The 15 kg of liquid faecal plumes, often white, orange or red and with a strong stench, are rich in nitrogen, phosphorus and other readily bio-available minerals. Sea birds such as Storm Petrels are the first on the scene to benefit from whale faeces, feeding on undigested crustaceans or cephalopods that have been released at the sea surface(5). Thereafter, the majority of faecal material disperses under the ocean surface and may sink within 1 hour(6). Faeces, concurrently to photosynthesis thus boost the production of phytoplankton, the first link in the food web, and a cornerstone of biodiversity. Fertilisation at the base of the food web increases the abundance of invertebrates and fish stocks. A university team from the east coast of the United States argues that because of this fertilization, the presence or transit of whales in a region actually leads to more abundant fisheries(7). Nitrogen and phosphorus discharged into the sea through human activities concentrate in estuaries and coastal waters. In contrast, during their migration, whales enrich areas of the high seas generally poor in plankton. If the populations of whales increased, they could help to counterbalance the decline in plankton linked to climate change.

3 – Sperm Whales as Iron Mines

The Sperm whale also plays an important role in marine ecosystems. The Southern Ocean population is estimated to be around 12,000 individuals. According to a recent study, this particular population of deep sea divers disperses 50 tonnes of iron, through their faecal matter, to the surface of the ocean on a yearly basis(8). When taking into account the latest estimates of the overall migrating population of 360,000 Sperm whales(9), the entire species would be spreading 1,500 tonnes of iron on the ocean’s surface per year. Iron is a nutrient which is crucial for the development of phytoplankton. Whales thus participate in iron redistribution. While Sperm whales in the 21st Century, one-tenth of the 20th Century’s population, continue to carry out this natural iron distribution in the ocean, geo-engineers are carelessly experimenting with distributing iron in plankton-deficient areas, or “dead” zones.

4 – Whales as a Carbon Sink

The ocean is by far the largest reservoir of Carbon – CO2 on the planet. Marine biomass plays a primary role in regulating the climate cycle of the Earth. The presence of iron and other nutrients such as nitrogen and phosphorus in whale faeces and other marine mammals enhances phytoplankton, and consequently improves carbon sink. The abundance and constant renewal of phytoplankton feeds back all marine life and therefore acts as a major carbon sink throughout centuries and millenniums. Australian scientists state that if the population of Sperm whales in the Southern Ocean were restored to pre-whaling stock figures, this population alone would help to store around 2.2 million tonnes (2,200 000) of CO2.(10)

Marine organisms store constant levels of carbon by feeding. Scientists show that the larger the animal, the more efficient it is in using energy and storing carbon. Because of this, whale carcasses that sink to the ocean floor export significant amounts of carbon to the deep sea and play an important role in sequestering carbon. According to American scientists, restoring the pre-whaling populations of eight important baleen whale species, the Blue, Fin, Humpback, Sei/Bryde’s, Minke, Gray, Right and Bowhead whales, would represent the storing capacity of an 110,000 hectare forest.(11)

5 – Whale falls create ecosystems

The environmental service given to the oceans by whales continues after their death. In the deep-sea, whale falls resemble oases in terrestrial deserts. A single whale carcass can feed species for several weeks – some of these scavengers such as grenadiers and sablefish also have a commercial interest. When the carcass undergoes the second stage of decomposition and reconversion, it generates complex ecosystems and tropic webs between fish, crustaceans, clams, worms and echinoderms. The third stage, which can last decades, is characterised by the implantation of specialised “sulphur loving”, bacterial colonies.

Sweden, Japan and the United States, thanks to research carried out by Craig Smith, have all carried out important and ground breaking work in this field. Robin des Bois compiled a document titled, “Of Whales and Their Usefulness”(12) on the subject.

The positive contribution of whales to the marine ecosystem and to stabilising the Earth’s climate should be taken into account and explored by the International Whaling Commission and by other international forums. From the cradle to the grave whales create positive impacts which contribute in a useful way to a balanced marine ecosystem.

Please see our first press release: Impacts on whales from radioactive inputs and debris following the tsunami, July 8th 2011

(1) Nelson, H.C., Phillips, R.L., McRea, J., Barber, J.H., McLaughlin, M.W., Chin, J.L. 1994. Gray whale and Pacific walrus benthic feeding grounds and sea floor interaction in the Chukchi Sea. U.S. Geological Survey.

(2) Nelson, H.C. and Johnson, K.R. 1987. Whales and walruses as tillers of the sea floor. Scientific American 256: 112-118.

(3) Oliver, J.S. and Slattery, P.N. 1985. Destruction and opportunity on the sea floor: effects of gray whale feeding. Ecology 66(6): 1965-1975.

(4) Roman. J. and McCarthy, J. J., 2010. The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal Basin. PLoS ONE 5(10).

(5) Davis, D. 1996. Humpback and Right whale migration update.

(6) Daley, B. 2006. The scent of a whale. The Boston Globe. http://www.boston.com/news/globe

(7) Roman. J. and McCarthy, J. J., 2010. The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal Basin. PLoS ONE 5(10).

(8) Lavery, T. et al., 2010. Iron defecation by sperm whales stimulates carbon export in the Southern Ocean. Proceedings of Royal Society B 277:3527-3531.

(9) Whitehead, H., 2002. Estimates of the current global population size and historical trajectory for sperm whales. Marine Ecology Progress Series 2002:295-304.

(10) Lavery, T. et al., 2010. Iron defecation by sperm whales stimulates carbon export in the Southern Ocean. Proceedings of Royal Society B 277:3527-3531.

(11) Pershing, A., et al., 2010. The Impact of Whaling on the Ocean Carbon Cycle: Why Bigger was Better. PLoS ONE 5(8)

(12) “Of Whales and Their Usefulness” [1]