Natural Products: Types Measured
The
Ocean Health Index measured six commodities to calculate Status and Trend for the
Natural Products goal. The sectors included were: Ornamental Fish, Seaweed and
Plants, Sponges, Shells, Fish Oil, and Coral.
Although it is a component of Natural Products within many countries, coral is not included here, but is incorporated in other models. Corals are assessed in association with multiple other goals, and within the Coral Reefs component page.
Although it is a component of Natural Products within many countries, coral is not included here, but is incorporated in other models. Corals are assessed in association with multiple other goals, and within the Coral Reefs component page.
Which Goals Does This Affect?
Ornamental Fish
'Ornamental
fish’ are species harvested and marketed for use primarily in home aquariums,
but also in commercial aquariums. Every
year, more than one billion ornamental fish are traded globally, 15 to 20
million of which are members of marine species (Weiner 2005). The number of
marine species traded has been estimated at between 1,400 and 8,000, most of
which are wild caught, unlike traded freshwater fish species, 90% of which are
farmed (FAO 2005-2012; Whittington 2007).
How Was It Measured?
Export
data were drawn from the Food and Agriculture Organization of the United
Nations (FAO) Global Commodities database for all available years, which
included 1976-2007 for ornamental fish. Data for the subcategories ‘Fish for
culture including ova, fingerlings, etc.’ and ‘Ornamental freshwater fish’ were
excluded. The two categories used were “Ornamental Salt Water Fish” and
“Ornamental Fish Not Elsewhere Indicated (NEI).” For the
monetary value data, nominal dollars ("observed measure unit - US
Dollar"), as reported by the FAO, were converted into constant 2008 USD
using CPI adjustment data (Sahr 2011; http://oregonstate.edu/cla/polisci/sahr/sahr).
What Are The Impacts?
ECOLOGICAL IMPACT
Ornamental
fish that are traded on a global basis can introduce pathogens to a new
environment. Contact with wild populations could be harmful if native species
have no resistance to the foreign disease.
The unsustainable harvest of ornamental fish can lead to habitat and/or ecosystem damage (e.g. coral reefs) if fish species are over-harvested or if destructive methods are used to collect them (e.g. cyanide, blast fishing).
The unsustainable harvest of ornamental fish can lead to habitat and/or ecosystem damage (e.g. coral reefs) if fish species are over-harvested or if destructive methods are used to collect them (e.g. cyanide, blast fishing).
HUMAN HEALTH IMPACT
No
direct impacts known.
ECONOMIC IMPACT
The
market for ornamental reef fish and coral has increased by 12-13% annually, and
the US comprises 80% of the importing market (Weiner 2005).
Two thirds of ornamental fish exports are derived from developing countries where fisheries often have an important economic role. However, certain fish stocks are often depleted due to overfishing and/or growing human population needs. Efforts are currently being made to minimize the harmful impacts of harvesting, as well as to replace wild caught species with farmed fish.
Ornamental specimens for aquariums are expensive, often costing 10 times or even 100 times as much as comparable organisms used for food or other purposes. For example, in 2000, one kilogram of aquarium fish from the Maldives was valued at nearly US $500, compared to only US $6 for one kilogram of reef fish harvested for food
(Wabnitz et al. 2003).
The high value of ornamental specimens translates into significant revenue for exporting countries. For example, approximately 50,000 people in Sri Lanka are directly involved in the export of marine ornamental reef fish to 52 countries, earning the country approximately US $5.6 million per year (Wabnitz et al. 2003).
Two thirds of ornamental fish exports are derived from developing countries where fisheries often have an important economic role. However, certain fish stocks are often depleted due to overfishing and/or growing human population needs. Efforts are currently being made to minimize the harmful impacts of harvesting, as well as to replace wild caught species with farmed fish.
Ornamental specimens for aquariums are expensive, often costing 10 times or even 100 times as much as comparable organisms used for food or other purposes. For example, in 2000, one kilogram of aquarium fish from the Maldives was valued at nearly US $500, compared to only US $6 for one kilogram of reef fish harvested for food
(Wabnitz et al. 2003).
The high value of ornamental specimens translates into significant revenue for exporting countries. For example, approximately 50,000 people in Sri Lanka are directly involved in the export of marine ornamental reef fish to 52 countries, earning the country approximately US $5.6 million per year (Wabnitz et al. 2003).
Seaweed and Plants
Seaweeds
and other marine algae can be harvested in their natural habitat or cultivated
in coastal waters or in tanks on land.
In the mid 1980s, seaweed farming became increasingly popular (vs. harvest from wild stocks) due to a significant rise in demand (Crawford 2002).
In the mid 1980s, seaweed farming became increasingly popular (vs. harvest from wild stocks) due to a significant rise in demand (Crawford 2002).
How Was It Measured?
Information used by the
Ocean Health Index to determine harvest and value for seaweed and plants is
from the Food and Agriculture Organization of the United Nations (FAO) Global
Commodities Database, which contains data on exports of
natural products by each country from 1976-2008.
Data categories used were: Agar agar in blocks, Agar agar in powder, Agar agar in strips, Agar agar nei, Carrageen (Chondrus crispus), Green laver, Hizikia fusiforme (brown algae), Kelp, Kelp meal, Laver dry, Laver nei, Laver smoked, Other brown algae (Laminaria, Eisenia/ Ecklonia), Other edible seaweeds, Other green algae (Ulva, Enteromorpha), Other inedible seaweeds, Other red algae, Other seaweeds and aquatic plants and products thereof, Rock laver, and Undaria pinnafitida (brown algae).
Sustainability of the harvest was measured as the intensity of harvest per km2 of a country’s potentially harvestable habitat. Exposure values were rescaled to between 0-1 using the global maximum intensity of harvest as the maximum value and 0 as the minimum value.
For the monetary value data, nominal dollars as reported by FAO ("observed measure unit - US Dollar") were converted into constant 2008 USD using CPI adjustment data (Sahr 2011 -http://oregonstate.edu/cla/polisci/sahr/sahr).
Data categories used were: Agar agar in blocks, Agar agar in powder, Agar agar in strips, Agar agar nei, Carrageen (Chondrus crispus), Green laver, Hizikia fusiforme (brown algae), Kelp, Kelp meal, Laver dry, Laver nei, Laver smoked, Other brown algae (Laminaria, Eisenia/ Ecklonia), Other edible seaweeds, Other green algae (Ulva, Enteromorpha), Other inedible seaweeds, Other red algae, Other seaweeds and aquatic plants and products thereof, Rock laver, and Undaria pinnafitida (brown algae).
Sustainability of the harvest was measured as the intensity of harvest per km2 of a country’s potentially harvestable habitat. Exposure values were rescaled to between 0-1 using the global maximum intensity of harvest as the maximum value and 0 as the minimum value.
For the monetary value data, nominal dollars as reported by FAO ("observed measure unit - US Dollar") were converted into constant 2008 USD using CPI adjustment data (Sahr 2011 -http://oregonstate.edu/cla/polisci/sahr/sahr).
What Are The Impacts?
ECOLOGICAL IMPACT
Intensive
harvest of wild seaweed can damage intertidal habitats if not properly
managed.
The methods used to cultivate seaweed are relatively low impact, especially if they are done off-bottom.
Seaweed cultivation can have a positive effect on fisheries by increasing local populations of herbivorous fish. However, it can have a negative impact on neighboring ecosystems (e.g. mangroves, coral reefs) by altering water flow and depleting nutrient sources.
The methods used to cultivate seaweed are relatively low impact, especially if they are done off-bottom.
Seaweed cultivation can have a positive effect on fisheries by increasing local populations of herbivorous fish. However, it can have a negative impact on neighboring ecosystems (e.g. mangroves, coral reefs) by altering water flow and depleting nutrient sources.
HUMAN HEALTH IMPACT
Seaweeds
and other marine algae are found as additives in animal feed, compost and
fertilizer, and as stabilizers, thickeners, emulsifiers, and supplements for
nutritional health or taste in food for human consumption (e.g. ice cream,
yogurt, mayonnaise). They are also used in cosmetics, toothpaste and other body
products.
ECONOMIC IMPACT
The
genus Porphyra includes approximately
70 species of intertidal red algae
used for human food or nutritional supplement and may be the most harvested and
cultivated type of seaweed worldwide. In
Japan alone, the cultivation of Porphyra
is said to be worth US $1 billion each year (Blouin et al. 2010).
Sponges
Sponges
are a diverse aquatic invertebrate phylum, with over 7000 living species found
in a wide range of marine environments. A few species (~150) live in
freshwater and brackish water, but the vast majority are marine, with different
species found from tropical coral reefs to arctic waters, and from coastal,
shallow waters to the deepest parts of the ocean (Lavrov 2009; Hogg et al.
2010).
Sponges are essential components for a healthy ecosystem in terms of their high biomass and water filtration and nitrification abilities. They also contribute to the biodiversity of habitats by providing shelter and breeding grounds for numerous marine species and microorganisms.
Although the increased use of artificial sponges has led to a significant decrease in commercial fishing for sponges, overfishing, disease and rising sea temperatures have all contributed to declines in local sponge populations over the past century.
Sponges are essential components for a healthy ecosystem in terms of their high biomass and water filtration and nitrification abilities. They also contribute to the biodiversity of habitats by providing shelter and breeding grounds for numerous marine species and microorganisms.
Although the increased use of artificial sponges has led to a significant decrease in commercial fishing for sponges, overfishing, disease and rising sea temperatures have all contributed to declines in local sponge populations over the past century.
How Was It Measured?
The
Ocean Health Index measurements are based on data for the number of tons of
sponges exported on a per country basis. The intensity of harvest per
km2 of potential habitat for a country was determined according to export
data (1976-2008) from the FAO Global Commodities database using the categories Natural
Sponges Not Elsewhere Indicated (nei), Natural Sponges other than raw, Natural
Sponges raw, and coral and rocky reef extent data from Halpern
et al. 2008.
For the monetary value data, nominal dollars ("observed measure unit - US Dollar"), as reported by the Food and Agriculture Organization of the United Nations (FAO), were converted into constant 2008 USD using CPI adjustment data (Sahr 2011 http://oregonstate.edu/cla/polisci/sahr/sahr).
For the monetary value data, nominal dollars ("observed measure unit - US Dollar"), as reported by the Food and Agriculture Organization of the United Nations (FAO), were converted into constant 2008 USD using CPI adjustment data (Sahr 2011 http://oregonstate.edu/cla/polisci/sahr/sahr).
What Are The Impacts?
ECOLOGICAL IMPACT
Bottom trawling fishing
methods damage and/or destroy sponge habitats and result in large instances of
bycatch.
Sponges provide biomass, structural habitat, water filtration and shelter for numerous species.
Deep sea sponge communities are not harvested commercially and are not included in the Ocean Health Index since global data are not available. Deep sea sponge communities are susceptible to damage by deep sea fish trawling. These communities are oases of biodiversity and shelter large populations of fish that are of commercial interest, but that are difficult to harvest sustainably, because the sponges that form their intricate architecture are very fragile, slow growing and may take a century or more to recover from damage (Hogg et al. 2010).
Sponges provide biomass, structural habitat, water filtration and shelter for numerous species.
Deep sea sponge communities are not harvested commercially and are not included in the Ocean Health Index since global data are not available. Deep sea sponge communities are susceptible to damage by deep sea fish trawling. These communities are oases of biodiversity and shelter large populations of fish that are of commercial interest, but that are difficult to harvest sustainably, because the sponges that form their intricate architecture are very fragile, slow growing and may take a century or more to recover from damage (Hogg et al. 2010).
HUMAN HEALTH IMPACT
Sponges
generate numerous concentrated compounds that are harvested for medical use.
ECONOMIC IMPACT
The
most commercially viable sponges are those that consist of soft fibers of
spongin protein [Demospongeae]. Overfishing has depleted populations of soft
sponges and prices have increased substantially. As a result, commercial sponge fishing has
suffered as more affordable synthetic substitutes now dominate the market for
human use.
Shells
‘Seashells’ are the hard outer casings (exoskeletons) made by marine animals for the protection and support of
internal organs. Although a number of marine groups, including Crustaceans
(e.g. crabs, lobsters), Echinoderms (e.g. starfish, sea urchins), Polychaete
worms, and others make exoskeletons, the term seashell typically refers to the
shells produced by marine Molluscs (e.g. clams, mussels, snails, conchs etc.);
this is how the term was used in the Ocean Health Index.
Seashells have been traded and collected for centuries for use in jewelry, decoration, religious ceremonies, and currency. Today, trade in shells, pearls, and shell products remain an important part of many local economies.
Seashells have been traded and collected for centuries for use in jewelry, decoration, religious ceremonies, and currency. Today, trade in shells, pearls, and shell products remain an important part of many local economies.
How Was It Measured?
The
Ocean Health Index measured the harvest of shells in terms of tons exported per
country according to the Food and Agriculture Organization of the United
Nations (FAO) Global Commodities database (1976-2007), using the listings for
Miscellaneous Corals and Shells, Abalone Shells, Mother of Pearl shells, Oyster
shells, Sea snail shells, Trochus shells and ‘Shells not otherwise listed’.
The intensity of harvesting (exposure) was calculated as tons exported per km2 of potential habitat. Potential habitat was estimated as area of coral reef and rocky reef using data from Halpern et al. (2008). Exposure values were rescaled to between 0-1 using the global maximum intensity of harvest as the maximum value and 0 as the minimum value.
For the monetary value data, nominal dollars, as reported by FAO ("observed measure unit - US Dollar"), were converted into constant 2008 USD using CPI adjustment data (Sahr 2011; http://oregonstate.edu/cla/polisci/sahr/sahr).
The intensity of harvesting (exposure) was calculated as tons exported per km2 of potential habitat. Potential habitat was estimated as area of coral reef and rocky reef using data from Halpern et al. (2008). Exposure values were rescaled to between 0-1 using the global maximum intensity of harvest as the maximum value and 0 as the minimum value.
For the monetary value data, nominal dollars, as reported by FAO ("observed measure unit - US Dollar"), were converted into constant 2008 USD using CPI adjustment data (Sahr 2011; http://oregonstate.edu/cla/polisci/sahr/sahr).
What Are The Impacts?
ECOLOGICAL IMPACT
The shells of living and/or dead mollusks provide
habitats for plants, invertebrates, small fish, and crustaceans (e.g. Hermit Crab). Vital habitats can be destroyed when disturbed by harvesters and/or
collectors in search of shell species.
Populations of some important shell species are in decline in certain areas, due to anthropogenic pressures such as overfishing, habitat destruction, and pollution.
Shells and shell fragments are an important component of some sandy beaches.
Populations of some important shell species are in decline in certain areas, due to anthropogenic pressures such as overfishing, habitat destruction, and pollution.
Shells and shell fragments are an important component of some sandy beaches.
HUMAN HEALTH IMPACT
Certain species of molluscs that are prized for
their shells can also produce clinically important toxins that are harvested
for medicinal use (e.g. Cone Snail).
ECONOMIC IMPACT
The harvest of shell species, and the subsequent
transformation into craftwork for the shell trade, provides a significant
source of jobs and livelihoods for coastal communities, particularly in
developing countries.
Fish Oil
Fish oil is a product of the fishing industry that is most commonly derived from
small, pelagic species of fish that have low market value for direct
consumption (e.g. anchovies, herring, sardines) (Tacon 2006). The oil can be
produced either from the whole fish or from its liver, and it is most often
sold as an ingredient for aquaculture feed, but is also used for human dietary
supplements.
The fish species that are used to produce fish oil are primarily wild-caught, and in many cases their stocks are being depleted due to unsustainable fishing practices. The fact that costs for fish, energy, fish processing and fishery resources are continuing to rise has also led to a decrease in the amount of fish oil and fishmeal used worldwide. As a result, some nations are currently exploring alternate methods of producing fish oil, which include utilizing krill populations. As krill themselves are a primary food source for many marine species, depleting their populations could affect ecosystem and food web structure. Certain types of algae, yeast and plants are also being considered as alternative sources for human dietary supplements and for possible for use as aquaculture feed.
Total production of fish oil in 2006 was 0.943 million tonnes, of which 88.5% was used as an additive to industrially compounded feed for aquaculture of shrimp and fish (FAO, cited in Tacon and Metian 2008).
The fish species that are used to produce fish oil are primarily wild-caught, and in many cases their stocks are being depleted due to unsustainable fishing practices. The fact that costs for fish, energy, fish processing and fishery resources are continuing to rise has also led to a decrease in the amount of fish oil and fishmeal used worldwide. As a result, some nations are currently exploring alternate methods of producing fish oil, which include utilizing krill populations. As krill themselves are a primary food source for many marine species, depleting their populations could affect ecosystem and food web structure. Certain types of algae, yeast and plants are also being considered as alternative sources for human dietary supplements and for possible for use as aquaculture feed.
Total production of fish oil in 2006 was 0.943 million tonnes, of which 88.5% was used as an additive to industrially compounded feed for aquaculture of shrimp and fish (FAO, cited in Tacon and Metian 2008).
How Was It Measured?
Data
were drawn from the United
Nations Food and Agriculture Organization (FAO) Global
Commodities database for 1976-2008, using the following categories: Alaska
pollock oil nei, Anchoveta oil, Capelin oil, Clupeoid oils nei, Cod liver oil,
Fish body oils nei, Fish liver oils nei, Gadoid liver oils nei, Hake liver oil,
Halibuts liver oils, Herring oil, Jack mackerel oil, Menhaden oil, Pilchard
oil, Redfish oil, Sardine oil, Shark liver oil, Shark oil, Squid oil.
The Status of fish oil production was calculated as the current harvest level relative to its (buffered) peak reference point, multiplied by the sustainability of the harvest.
Sustainability was calculated primarily by the weighted proportion of species harvested sustainably, i.e. the number of species in each exploitation category (developing, fully exploited, overexploited, collapsed or rebuilding) as defined by FAO and Sea Around Us (Kleisner and Pauly 2011), and weighted by category.
Trend was calculated as the change of Status over the five most recent years of data.
The Status of fish oil production was calculated as the current harvest level relative to its (buffered) peak reference point, multiplied by the sustainability of the harvest.
Sustainability was calculated primarily by the weighted proportion of species harvested sustainably, i.e. the number of species in each exploitation category (developing, fully exploited, overexploited, collapsed or rebuilding) as defined by FAO and Sea Around Us (Kleisner and Pauly 2011), and weighted by category.
Trend was calculated as the change of Status over the five most recent years of data.
What Are The Impacts?
ECOLOGICAL IMPACT
The
fish species that are used to produce fish oil are primarily wild-caught, and
in many cases their stocks are being depleted due to unsustainable fishing
practices. As these small, pelagic species tend to be a primary food source for
many marine species, depleting their populations could affect ecosystem and
food web structure.
HUMAN HEALTH IMPACT
Fish
oil is often used as a human dietary supplement because the oil derived from
certain species tend to be rich in omega-3 fatty acids, which are believed by
many to promote a healthy cardio-vascular system. These cardiovascular
benefits are attributed to the fact that the presence of omega-3s in the blood
inhibits the formation of blood clots and reduces inflammation in the blood
vessels.
These supplements should be taken with doctor’s approval and may have side effects.
These supplements should be taken with doctor’s approval and may have side effects.
ECONOMIC IMPACT
The
fact that costs for fish, energy, fish processing and fishery resources are
continuing to rise has led to a decrease in the amount of fish oil and fishmeal
used worldwide.
References
ASOC.
(2010). The Need to Reduce Uncertainties in the Antarctic Krill Fishery.
Campbell, J. and Simms, J., 2009, ‘Status report on
coral and sponge conservation in Canada’, Fisheries and Oceans Canada: vii 87pp
Corriero,
G., Longo, C., Mercurio, M., Marzono, C., Lembo, G., and Spedicato, M., 2004,
‘Rearing performance of Spongia
officinalis on suspended ropes off the southern Italian coast’,
Aquaculture, no. 238, pp. 195-205.
Crawford, B.R (2002). Seaweed farming: An Alternative Livelihood
for Small-Scale Fishers? Proyek Pesisir Publication. University of Rhode
Island, Coastal Resources Center, Narragansett, Rhode Island, USA.
Diaz, M.,
and Rützler, K., 2001, ‘Sponges: an essential component of Caribbean coral
reefs’, Bulletin of Marine Science, vol.
69, iss. 2, pp. 535-546.
Donia, M.
and Hamann, M. 2003, ‘Marine natural products and their potential applications
as anti-infective agents’, The Lancet
Infectious Diseases, vol. 3, pp. 338-348.
Dunstan, A., Bradshaw, C., Marshall, J., 2011, ‘Nautlius
at risk – estimating population size and demography of Nautlius pompilius’, PLos ONE, vol. 6, iss. 2.
Jereb, P., ‘Chambered nautiluses’, in Jereb, P., and Roper, C. (eds), Cephalopods of the world, an annotated and illustrated catalogue of cephalopod species known to date, vol. 1, 2005, Food and Agriculture Organisation of the United Nations, Rome.
Gallardo, W., Siar, S., and Encena, V., 1995,
‘Exploitation of the window-pane shell Placuna
placenta in the Philippines’, Biological
Conservation, vol., 73, no. 1, pp. 33-38.
Hogg, M.,
Tendal, O. Conway, K., Pomponi, S. van Soest, R., Gutt, J., Krautter, M. and
Roberts, J., 2010, ‘Deep-sea sponge
grounds: reservoirs of biodiversity’, UNEP-WCMC Biodiversity Series No. 32,
UNEP-WCMC, Cambridge, UK.
Jagadis, I., Syda Rao, G., Joshi, K., and Kandan, P.,
2010, ‘Fishery and populations of the sacred chank Turbinella pyrum (=Xancus
pyrum Linneaeus, 1758) off Kayalpattinam in the Gulf of Mannar’, Indian Journal of Fisheries, vol. 57,
no. 3, pp. 1-5.
Jenkins,
D. J.A., John L. Sievenpiper, Daniel Pauly,
Dr rer nat, Ussif Rashid Sumaila,Cyril
W.C. Kendall, Farley M. Mowat (2009). Are dietary recommendations for the use of fish oil sustainable? CMAJ
vol. 180 no. 6 doi: 10.103/cmaj.081274
Kleisner,
K. and Pauly, D. (2011). Stock catch status plots of fisheries for regional
seas. Pp. 37-40. In: V. Christensen, S. Lai and M. Palomares (Eds.)
The State of Biodiversity and Fisheries in Regional Seas. Fisheries Centre
Research Reports. University of British Columbia, Vancouver, Canada.
Laport, M.S., O.C.S. Santos and G.
Muricy. 2009. Marine Sponges: Potential
Sources of New Antimicrobial Drugs, Current Pharmaceutical Biotechnology, 2009,
10, 86-105
New M. B., and Ulf N. Wijkström. (2002)
Use of Fishmeal and Fish Oil in Aquafeeds
Further Thoughts on the Fishmeal Trap. FAO. Rome, Italy.
Osinga, R.,
Sidri, M., Cerig, E., Golkap, S., and Gokalp, M., 2010, ‘Sponge aquaculture
trials in the East-Mediterranean Sea: new approaches to earlier ideas’, The Open Marine Biology Journal, no. 4,
pp. 74-81.
Pettit, R.,
Fakoury, B., Knight, J., Weber, C., Pettit, G. Cage, G., and Pon, S., 2003,
‘Antibacterial activity of the marine sponge constituent cribrostatin 6’, Journal of Medical Microbiology, vol.
53, no. 1, pp. 61-65.
Stansby, Maurice E. (1988). "Fish
oil research, 1920-87, in the National Marine Fisheries Service, NOAA." Marine Fisheries Review 50.4: 174+. Global Reference on the
Environment, Energy, and Natural Resources.
Web. 5 Mar. 2012.
Stevely, J.,
Sweat, D., Bert, T., Sim-Smith, C., and Kelly, M., ‘Commercial bath sponge (Spongia and Hippospongia) and total sponge community abundance and biomass
estimates in the Florida Middle and Upper Keys, USA’, Proceedings of the 61st
Gulf and Caribbean Fisheries Institute, November 10-14, 2008, Gosier,
Goudeloupe, French West Indies.
Sugiyama, S., Staples, D.
& Funge-Smith, S.J. 2004. Status and
potential of fisheries and aquaculture in Asia and the Pacific. FAO
Regional Office for Asia and the Pacific. RAP Publication 2004/25. 53 pp.
Tacon,
A.G.L., Mohammad R. Hasan, and Rohana P.
Subasinghe (2006). Use of Fishery Resources as Feed Inputs to
Aquaculture Development: Trends and Policy Implications. FAO. Rome, Italy.
U. T.
Srinivasan, W. W. L. Cheung, R. Watson, U. R. Sumaila. (Journal of Bioeconomics, 2008), vol. 12, pp.
573-583.
Wabnitz, C., Taylor, M., Green, E., Razak, T. 2003.From Ocean to Aquarium. UNEP-WCMC, Cambridge, UK.
Webster, N.
2007, ‘Sponge disease: a global threat?’, Environmental
Microbiology, vol. 9, pp. 1363-1375.
Weiner,
D., & Borneman, E. (2005). Reef Protection International. Earth Island Journal, 19(4), 17.
Wells, S., 1981, ‘International trade in ornamental
shells’, International Union for Conservation of Nature and Natural Resources,
Cambridge, UK.
PHOTO(S): © Keith A. Ellenbogen