Are Sea Sponges Sustainable & Ethical?

Sea sponges, or natural sponges, are simple aquatic animals, though they’re often mistaken for plants.

They live primarily at the bottom of the ocean attached to rocks and coral reefs (which are also animals, by the way), though broken pieces of sponge can also attach themselves to floating debris like plastic and continue to grow.

Their sponginess comes from the fact that their bodies are full of pores and channels allowing water to pass through, providing both food and oxygen. Not all types of sea sponges are soft though. Only the ones with soft, fibrous skeletons made of “spongin”. Out of the 8,550 or so sponge species, only a handful of soft sponges are harvested for human use.

Natural Sponges Vs Synthetic Sponges

Most manufactured sponges are either made from plastic (mainly polyester and polyurethane foam) or cellulose (wood pulp) combined with other natural fibers.

Plastic sponges (like those ubiquitous green and yellow kitchen sponges) are an ecological nightmare, taking a long time to break down and shedding microplastic fibers along the way—approximately 6.5 million fibers per gram of worn-out sponge! These microplastics not only pollute the environment but get consumed by aquatic life (natural sponges included) and pollute the entire food chain—you included.

Plus, many “antibacterial” and “odor-free” sponges are impregnated with the chemical Triclosan, linked to various health concerns so much that the FDA recently banned it. It can also leach into waterways and cause harm to marine wildlife.

It’s possible to make cellulose sponges without any plastic or toxic chemicals so they’re a much better option than plastic ones. Sea sponges, however, are the most natural of all, with minimal processing needed between the harvesting and retail stages.

Sea sponges are 100% natural—meaning they’re also 100% compostable—putting them right at home in any zero waste bathroom. As with most things, however, scrubbing away at the issue doesn’t just leave us with something sustainably shiny underneath.

Remeber, not are sea sponges alive, but they play an essential role in the marine web of life, namely supporting coral reefs. They filter water, provide structural support and help keep reefs clean. They do such a good cleaning job (filtering between 2m3 and 20m3 of water per kg of body weight every day) that researchers are looking into whether sponges can be used to filter contaminants on an industrial scale.

If sponges play such an important role in keeping marine ecosystems healthy, should we really be removing them and what are the con-sea-quences if we do?

Sustainable Sea Sponge Harvesting & Farming

Before we talk about the sustainabilty of harvesting them, are sea sponges endangered?

Very rarely. The majority of sponges are not endangered. Only 20 out of the 8,500+ species are on the threatened species list, although there is a call for more research, particularly on the effects of environmental pollution on sponge populations.

While the commocean some folks raise about the sustainability of sponges and over-harvesting practices is well placed, it’s important to recognize that sponges can be harvested and farmed sustainably if properly monitored and controlled. And unlike in days gone by, sponges are now often harvested sustainably in a way that allows the sponge to regrow. Like coppicing trees, sponge divers cut off the top part and leave the base intact so it will regenerate over a period of 3-5 years.

Areas that were previously closed for the tune of 70 years due to over-harvesting have now reopened due to the industry’s focus on regrowth and sustainability.

Natural sea sponges can also be sustainably farmed via a fascinating process. First, the tops of sponges are sustainably harvested. This is then divided into several pieces or “transplants” that are tied to long lengths of rope and submerged in underwater hanging gardens. It takes 2-3 years for the transplants to grow into sponges that are ready for sale.

Sponge farming can be both sustainable and fair trade. One sustainable sponge farming project in Micronesia supports local marine farmers to produce bath and facial sponges, providing an income for local communities. Another on the East Coast of Zanzibar works with mainly single women, helping them secure stable income for their families.

Sustainable Sea Sponge Processing

While sea sponge processing is more minimal than most sponge substitute products on the market, there is still some risk of some not-so-eco friendly practices.

First, the end product is the soft skeleton of the sponge after its tissues have been removed. Then they’re cleaned before sale. Depending on the company, that can mean through either earth-safe detergents or harsh chemicals. Sponges are also sometimes bleached to change their color, the use of which pretty much negates any benefits of the sponge itself.

The most eco-friendly sea sponges are those that have been minimally processed without the use of harsh chemicals or bleach. While many natural sponges are indeed sustainable, picking the right one requires a little more leg work than just picking one blindly off the shelf. Specifically, look into the brand’s harvesting and processing methods.

Natural sponges are a better choice for the environment, especially compared to their plastic-based counterparts. However, given that they are living creatures, is it ethical to harvest and farm them? And moreover, since many people in sustainability circles try to abstain from animal products altogether, an even more pressing question arises: are sponges vegan and cruelty free?

Technically no, they’re not vegan. They’re classed as an animal and therefore those who staunchly avoid animal products may want to avoid sponges, too.

But there is an argument to be made that natural sponges are cruelty-free. See, sponges are a simple multi-celled organism. That means they don’t have a nervous system, circulatory system, or organs like other animals. Given there are no nerve cells, removing the top part of a sponge is likened to us having a haircut, so long as the base is left intact to regenerate.

Considering all of the above, some people who would typically avoid animal products may actually be okay using sponges (similar to those who use ethically sourced beeswax as it doesn’t harm the bees). Ultimately, it comes down to individual choice as to whether you let these drift into your zero waste cleaning routine or not.