Coming To a Remote Spot Near You…

It's a pristine place, right-

It’s a pristine place, right?

In my experience long distance cruisers are great lovers of the marine environment, whether it be clean seas, marine wildlife or their favourite wild places. If that is indeed true, we’d be the last people to want to cause harm to pristine places, either deliberately or unwittingly. And yet, as I recently learned, the latter may indeed be the case, even though we have no idea at all that we may be doing it. And it’s all down to the critters that hitch a ride with us on our hulls—Invasive Non-Native Species, INNS for short.

But foreign creatures have always hitched a ride on ships, haven’t they?

Indeed they have, from ocean going timbers of old to the ballast water ships take in on one side of the world and discharge in another.  There are many well-known cases; one that I know only too well being that of the (originally) US-based slipper limpet that is choking the native oyster beds in our home port of Falmouth, Cornwall.

In the US a sea squirt that is common in British waters called Ciona intestinalis is proving to be a real pest. It’s a universal problem that urgently needs addressing.

Surely climate change will also have an effect?

Although it’s likely that with rising sea water temperatures the numbers of invasive species will naturally increase, this should take place over a far longer time frame than is currently being witnessed, due to the natural processes and distances involved, which normally allow adaptation and predation to take place along the way, diminishing the threat.

So the focus is now falling on smaller craft that either carry such immigrants on a local basis, or even from further afield—like ocean going yachts. In order to get a handle on the scale of the problem, I turned to one of Britain’s experts in this field, my old friend Sarah Brown, herself an active sailor.

Is this a serious problem?

Definitely – many of these species will have endured a long sea journey, often in hostile conditions and so are real survivors, well able to adapt to local conditions and out-compete local species. It’s also important to recognize that there is a big difference between a non-native species and an invasive non-native species—the local environment can often adapt and accommodate the former, whereas the latter will tend to take over. And where a habitat is already degraded from other problems such as pollution, INNS are well placed to exploit any weaknesses and can become a real threat.

In what way are yachts implicated in all this?

Although the major threat for bulk transmission remains from commercial vessels, big and small, these craft tend to make journeys from port to port, and only stop for short periods. Yachts tend to moor up in ports or marinas for weeks or months, and may then visit pristine remote areas, and stay there for longer periods allowing INNS to settle.

There has been a lot of research in this field, including one well-respected study that identified recreational vessels from the south coast of the UK as having an average of four different INNS on their hulls. Further north the average number dropped, an effect either due to temperature or boat movements. And yet these were relatively clean hulls to the naked eye. This suggests that yachts certainly have the potential to move INNS species about, without even being aware of it.

OK, are there active measures we can take?

Yes—check, clean and dry is the best course of action. Check your hull for fouling and clean it off before you leave an area, preferably ashore where the run-off can be cleared away to landfill.

If you can’t do that, then try to scrub off in deep water where there is a smaller chance of any INNS species getting a foothold. Clean your anchor, dinghy and kit to remove any plant and animal matter, and wash it down with clean water if possible. Hot water (over 40° C) will kill most things, so if you can pressure wash with hot water that is good too. And if it’s all that’s available, do your best with local seawater.

Cleaning the hull – Many marinas have facilities to gather and dispose of waste water.

Cleaning the hull – Many marinas have facilities to gather and dispose of waste water.

Dry all you can. Very few species can handle desiccation. Obviously this is easier in warmer climates, but it can be effective anywhere.  And remember, too, that most marine species can’t cope with fresh water, so periodically going into a canal, estuary or river can be helpful.

Could you foresee the threat of INNS resulting in yachts facing restricted access to Marine Conservation Zones or Marine National Parks?

This might happen if there was evidence that showed that yachts were a key vector for invasive species. In fact, some Governments have already discussed such measures. For example, in New Zealand you must have your boat inspected, and in the event that it is carrying INNS it can be impounded. And in the UK we already have legislation to do something similar, although these powers have yet to be used.

It used to be such a simple life!

But it ain’t any more. Not that I’m making light of what is clearly a serious matter, and Lou and I would be the last people to ignore anything that could reduce our impact on the marine environment. So we’ll take on board this advice, and do our best to comply.

Partly this is because the further we travel, the more threats to the ocean we see—overfishing, industrial scale fish farming, oil and gas installations, nuclear power plants and people, people, people! We want to see pristine, unspoiled places and waters, but they’re becoming harder to find all the time—and that’s a great shame.  So whatever small contribution we can make, we will, and let’s hope it makes a difference. Otherwise we may all face further restrictions to our cruising plans—and I’m sure we’d none of us want to see that happen.

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Meet the Author

Colin Speedie

Colin, European Correspondent here at AAC, is a deeply experienced offshore sailor who holds a Yachtmaster licence, and a gifted photographer and talented writer who has added a whole new dimension to Attainable Adventure Cruising. In addition, since Colin and Louise are from England and had their OVNI 435, Pèlerin built in France, they bring a European perspective to our site. You can read more about Colin and Louise and their business at their website.

Comments on this entry are closed.

  • Daria Blackwell Jun 19, 2013, 3:05 pm

    Hi Colin,
    Really good article. Important. We have serious issues with invasive species in Ireland and had them with zebra mussels in the States. It really is a problem.

    But how realistic is it to haul a boat, wash a hull (with fresh water) and dry it before sailing off to the next destination in most remote places? There has to be a more practical solution for it to be effective. A new bottom paint. An ultrasonic ‘scouring’ method? Ultraviolet light. Bio-containment field? Whatever will work for the majority of INNS. And for cruisers, it has to be inexpensive. 🙂

    • Colin Speedie Jun 19, 2013, 7:58 pm

      Hi Daria

      Glad you found the article useful – and I agree that it is a problem.

      I also accept that there is no simple, convenient, cost effective magic bullet that will address all concerns and all species – yet, at least. So we must do the best we can with all the means currently at our disposal until better technical solutions come to the market than are currently available. As the co-owner of an aluminium boat I’m hoping it will be a paint based solution!

      But, as is always the case in these matters, the ‘do-nothing’ option is no option at all, and I believe that it is in all of our interests to do what we can, (including lobbying paint manufacturers) because (a) we share the planet, and (b) otherwise ill informed legislators may force the wrong actions upon us – and not for the first time.

      Best wishes


  • Chris Jun 19, 2013, 5:22 pm

    John, With all due respect and friendship, I am reminded of the argument that all littoral sewage pollution is the fault of yachts. It is patently false, and it is still very alive and disgustingly well as an argument to drive us away from localities or into marinas where our wallets can be deeply harvested. [We have a 75 gallon holding tank and only pump out or dump tanks where legal.]

    I am reminded of one large western Florida community particularly hateful toward cruisers. In the same newspaper that characterized how dangerous we are to the environment was an article about the release of several million gallons of raw sewage (through the local mooring field) from a overtaxed processing plant — regretfully focused on how expensive it would be to repair without outside government intervention.

    One resort in the Abacos is still blaming all the reef killing runoff pollution from its heavily fertilized and watered golf resort (on an island with no freshwater supply) on the six to ten cruising boats that can anchor in the area at any given time.

    I believe such is the case with the idea that yachts (of the kind usually discussed on this site) contribute in any significant way to species invasion. Tons of ballast water is a very different invasion mechanism than the release of eggs, sperm and spores from the sedentary fauna and floral found on 40 to 80 sqm cruising boat hulls.

    If anyone has given their hull a speed enhancing scrub before setting off, the very very great majority of reproduction capable organisms have been removed in their own biome — a bacterial slime is about all that is left. A hull cleaned thusly will arrive with a burgeoning population of open ocean fouling — which has been occurring since flotsam has been floating.

    Two technical points. Freshwater will not kill most marine fouling organisms outright. These animals and plants live in the first meter of seawater where rain and ice melt frequently generate brackish to fresh conditions (lenses) for extended periods — not to mention littoral runoff from rivers, streams and sewage plants. If we must spray the hull, hot seawater is just fine — if hot can be found. Also drying the hull isn’t completely helpful. Many of these organisms from the intertidal zone can stand drying in hot sun for a tidal cycle and quite a few reproduce from spores with even greater tolerance to drying.

    While I would never say this is categorically not an invasion vector just as I would never say there aren’t dirt-bag cruisers who pump overboard where they shouldn’t, this is another area where we don’t need to paint an unearned bulls-eye on our transoms (personal and boat).

    We have always been low-hanging fruit for ill informed and misguided regulators. I’d hate to see that happen again.

    • John Jun 19, 2013, 5:55 pm

      Hi Chris,

      Just to clarify, Colin was the author of this post, not me. Not trying to duck here, just making sure there is not a misunderstanding, particularly since Colin has spent a huge amount of time in the environmental business and is well qualified to talk about such issues and I have not and am not.

      • Chris Jun 19, 2013, 6:16 pm

        My apologies to you both. I have a template and forgot to change the name. My respect and friendship applies in both cases.

        • Colin Speedie Jun 19, 2013, 8:11 pm

          Hi Chris

          I agree with much of what you say – there’s no question that the cases you offer represent the more egregious examples of scapegoating, usually to conceal a hidden agenda or to divert attention from failings closer to home. And my post does not set out to concede anything to the perpetrators of such greenwash. Let’s consider, for comparison, the effect of the discharges from one cruise ship on a coral atoll, or the run-off from agriculture on the Great Barrier Reef.

          As you say yourself, we cannot say categorically that there is no case to answer for yachts – more research is needed and will undoubtedly help. And as I agreed with Daria (see above), you’re right that the ‘solutions’ at our disposal at present are far from comprehensive or ideal. But I’d guess that you, I and most of the people who read AAC would (in my view) be the sort of people who would rather take practical action to become part of the solution using whatever means are the most effective – which I believe is our best form of action in every sense, and we’re smart enough to choose the most effective options – if we’re informed, that is – and that’s what I’m hoping to achieve here.

          Thanks for a very worthwhile comment.



          • Chris Jun 20, 2013, 9:45 am

            Thank you, Colin

            It seems to me it is important to differentiate contained transportation and uncontained. There is no good excuse for not treating or cleaning bilges, live wells, etc before setting out locally or internationally. Bathroom sanitizer of the most pedestrian sort will do the job and leave a pleasant scent (he said, wryly).

            There is not a good, data-based case for uncontained (hull fouling) transportation on cruising yachts being a problem. But lack of data has never stopped those who regulate from fear of the worst. And the tendency is minimize maximum regret — because one species might be transported, all opportunities for transportation must cease. Movement back to a more reasonable, balanced position can take decades if the defendant lacks deep pockets. In the mean time, cruisers are left to bear the burden of the unreasonable.

            Here in Florida (the poster child for centuries of environmental abuse and knee jerk regulation) it is becoming increasingly necessary to show a receipt for commercial pump out service less than 5/10 days old to be allowed to anchor or moor. There are jurisdictions that are attempting to make lack of possession of such a receipt grounds for interdiction regardless of intention to moor — in other words, to deny free passage. [The worst recent marine invasion here? The lion-fish — the vector, aquairists dumping their voracious pets in the littoral rather than in the dust bin.]

            It is easy to imagine that similar action could evolve from a hysterical dialog on cruising yacht bottom fouling. “Let us see your receipt for a scorched bottom less than x days old, or we will impound…”

            So for the cruising communities’ sake, it would be good to get out ahead of this one for a change. What makes this ironic is, after the racing community, we are perhaps the most interested in clean bottoms for their rewards of speed, maneuverability and fuel efficiency.

            I think I am becoming repetitive here. I think I will stop before I become shrill.
            OBTW, as for silver bullets, we’ve had them and they have been regulated out of use — organo-tins, illegal; veterinary antibiotics, illegal; suspended copper, under pressure for criminalization.

  • Matt Marsh Jun 19, 2013, 11:07 pm

    Thanks for bringing this up, Colin; it’s an easy thing to forget.

    Being from Ontario, the zebra mussels are the first thing that comes to mind. When they first arrived, they spread like wildfire in the Great Lakes. They killed off a lot of native species and everyone spent a fortune cleaning them from hulls, water pipes and so forth.

    However, due mainly to an extensive public education campaign teaching boaters and anglers about their life cycle and how to prevent their spread, many (if not most) of our ~250,000 lakes are still zebra mussel free.

    Pollution is a different matter- one where scale really does matter- but when it comes to invasive species, it only takes one careless boater to forget to flush a livewell or rinse down a trailer before switching lakes, and POOF! Invasion.

    • Colin Speedie Jun 20, 2013, 9:48 am

      Hi Matt

      There’s no doubt this can be a major problem, and it’s great to hear that the educational programme generated action that seems to have contained the problem. And a useful reminder that we can all take meaningful action.

      Best wishes


  • Sarah Brown Jun 20, 2013, 7:54 am

    Hello all,

    thanks for the article Colin, it makes interesting reading. I have worked on this issue for a number of years and am close to those making the legislation in the UK. So far they are keen to follow the ‘voluntary’ /educational approach and not encourage un-enforceable regulation. At least in a UK context. Laws do exist in Scotland and other places which could see vessels impounded if they were suspected or known to be harbouring nasties however and I suspect this sort of emergency measure will be adopted widely in the near future.

    With regards to recreational vessels – it is really important here to stress that these boats are one of the more common vectors for moving species locally, they are not thought to be the way species are transported internationally, although that is possible and certainly seemed to be the case with Zebra mussel in Ireland.

    You mention a ‘magic bullet’, these do exist – really. They are working on a toxin which will be ingested by harmful species (which tend to be much less choosy about their food) and rejected by native (fussy) species. This technology relies on the species response to particulate size and
    lipid content and has as many questions about its long term effect, law of unintended consequence and all that.

    This is an issue for all sea users and we, as boaters, must play our part.

    Best wishes


    • Colin Speedie Jun 20, 2013, 9:51 am

      Hi Sarah

      Thanks for the clarification of the situation re legislation in the UK (at least), which I suspect will soon find traction in other countries – if not already.

      Also the fascinating insight into the state of research – presumably, the toxin would be delivered via a paint system (i.e in the antifoulant?).

      Best wishes


      • Sarah Brown Jun 25, 2013, 8:52 am

        Hi Colin, the magic bullets would be released into the food chain as suspended matter in the water. It has proved effective against zebra mussels (this is what it was designed for) in trails in lab conditions. I do not know if it has been trailed in the real world yet.

        • Colin Speedie Jun 25, 2013, 11:39 am

          Hi Sarah

          Thanks for the explanation, and I’ll look forward to hearing more on this subject as the science catches up with the problem.

          Best wishes


  • Ron Jun 20, 2013, 9:25 pm

    Hi Colin,

    Very interesting article. My wife and I just started full time cruising. We have done just about everything we can to make our boat as environmentally friendly as possible. We use anti fouling with out copper, we have equipped our boat with solar & wind generators, we even went so far as to install a composting toilet so we never discharge and solid waste, unless its in a dumpster. We have an electric outboard so there’s no chance of a fuel spill ( or explosion for that matter). I think that if everyone paid attention to their impact on the environment things wouldn’t be this bad.

    Thanks for all the great information,
    Ron Brown

    • Colin Speedie Jun 22, 2013, 9:40 am

      Hi Ron

      It certainly seems you’ve gone the extra mile.

      Like you we’ve always taken the view that we should minimise our impact on the marine environment, and we do our best. But I’ve no experience of composting marine toilets, and I’d be interested to hear how well they work, especially for cruising long distances.

      And I agree that it’s up to all of us to do our bit – for all of the reasons that have been outlined in the great comments above.

      Best wishes


      • Ron Brown Jun 22, 2013, 10:55 am

        We are kind of minimalists. Our boat does not have aircon nor does it have hot water (unless you boil it). We figure go north when it’s hot, south when it’s cold. However we do have a wood stove on board, and that has an EPA rating.

        The composting toilet is not for everyone. Although we are completely happy and would never want to go back to a holding tank, it is a compromise just like everything else. We don’t have to pump out, but we do have to empty the liquid waste bottle about every other day. According to the manufacturer the liquid waste is inert and does no harm. This we dispose of in toilets when at a marinas or overboard when not. We spent a winter on the Chesapeake Bay and over the course of five months we emptied the solid waste twice. For two people it works well, for a larger crew you could quickly overwhelm it. When we do remove the solids it has the consistency of very fertile dirt, smells musty and we place it in a trash bag and throw it in a dumpster, or I guess at sea we’d have to dump it overboard but it is simply dirt at that point. Also if you have guests they must be instructed on how to use it and cautioned against using it if seasick! Like I said its not for everyone but it suits our needs.

        Best Regards, Ron

        • Colin Speedie Jun 23, 2013, 9:55 am

          Hi Ron

          Thanks for the lowdown on the composting heads- Much appreciated. I’ve always wondered how they worked in practice.

          Best wishes


        • RDE Jun 23, 2013, 11:06 am

          Hi Ron,
          I second your positive comments about composting heads based upon using a similar system for two weeks in the Bahamas.

          On the other hand, I think Freud provided the proper term to describe our modern attitude toward human waste— Anal Compulsion. Direct discharge is certainly not appropriate for a crowded anchorage or a stagnant bay with little tidal action. But consider the marina where I lived aboard for several years: Shilshole Bay Marina (Seattle) fronts on Puget Sound, protected by a breakwater. It houses about 1500 boats, with perhaps 100 live-aboards. At no time did I ever notice a foul odor, and I’m sure there were many people illegally pumping overboard just as I did. On shore are businesses and a large parking lot with over 2,000 vehicle spaces.

          Which do you think is more harmful to marine life, toxic bottom paint designed to kill marine growth leaching from 1500 boat bottoms, oil and brake residue from 2,000 cars, storm runoff from the city drains that led directly into the ocean, or the biological nutrients that I contributed to the crabs and marine organisms every time I flushed my head?

          • John Jun 23, 2013, 2:09 pm

            Hi Richard,

            Your comment makes a lot of sense, I agree completely.

            One thing, my dyslexia kicked in and I misread the name of the marina, which certainly gave me pause for thought!

        • Alan Teale Jun 24, 2013, 3:56 pm

          Hi Ron, We are installing a Nature’s Head on a new build boat for our own use, although we have no previous experience of composting toilets. We went that way to avoid a black water tank and the plumbing that comes with flush toilets, which we both consider abominations on a boat. I would be interested to know what organic “additive” you use, my understanding being that peat moss and coconut coir are the usual choices (although peat moss is quite rightly, for obvious reasons, becoming difficult to purchase). And do you use an organic drain cleaner in the toilet to catalyse the action? Alan

          • Ron Brown Jun 24, 2013, 9:33 pm

            Hi Alan,

            The media we use in the solid waste tank is crushed coconut husks. You can purchase bags of it from pet stores. They use it in snake pens. You can also use peat moss. Also to aid in digestion we add a septic tank treatment. It is sold at most hardware stores or Home Depot. The problem with peat moss is finding it in small enough quanities. Most garden centers want to sell it to you in 50 lb bags. I’ll tell you that’s enough for a couple of years. I like the design of the Natures Head with the exception of the liquid waste tank. To remove it you have to expose the solid waste section which might create some odors if you aren’t fast enough. Just a word of caution, make sure any openings for ventilation in the Natures Head toilet are sufficiently screened. The reason is bugs. We read one account of a woman complaining about bugs in her toilet and it was a Natures Head. But we have friends that purchased an Air Head and they had problems with bugs..but they also didn’t keep the lid closed so it was open to anything small with wings. We also (once) had problems with very small flying bugs. They were more a nuisance than anything else and were easily removed by changing the media. My wife found out what they were from a garden composting website. So when we remove the liquid waste bottle we place a small tissue in the opening to eliminate any chance of bugs. All in all it does make boating a little simpler. If you have any other questions we’re happy to help.

            My wife and I are interested in what kind of boat you are building and where you plan to sail.

            Regards, Ron

        • Alan Teale Jun 25, 2013, 3:52 pm

          Hi again Ron, “Kiviuq” is an alloy van de Stadt Madeira 46 (the 44 with a scoop stern). She is intended for a circumnavigation of the Americas. She has a designed black water tank, which being a skin tank on the centreline in a deep part of the hull we can now make use of as a heat sink for the fridge compressor coolant. We prefer coolant in the tank rather than human waste. However, just in case we can’t get on with a composter we have future-proofed for a Lavac installation. We are pretty determined to make the Natures Head work for us though. My sense is that a composter requires a little more involvment with what most people prefer not to think about, but as we both have medical backgrounds we don’t anticipate any broadening of horizons on the toilet front. My thanks to you for relating your experience. Alan

          • Ron Brown Jun 25, 2013, 7:02 pm

            Hi again Alan,

            Good luck with your boat, it sounds great. FYI on the medical front, 2 people on board; with a stomach/intestinal flu will be a challenge with a composter. After that unfortunate experience, we keep “Doodie Bags” on hand available at West Marine or most camping stores. These will help in such an emergency.

            Good Luck & Fair Weather, Ron Brown

          • Colin Speedie Jun 25, 2013, 7:25 pm

            Hi Ron and Alan

            Thanks Ron for the excellent and honest appraisal of the composting heads – I’m sure we’re all the wiser for it.

            Alan – nice boat!

            Best wishes


  • RDE Jun 22, 2013, 11:52 pm

    Hi Colin, With your background in marine research and recent passage through this patch of ocean you might be interested in following this research project.

  • Colin Speedie Jun 23, 2013, 9:53 am

    Hi Richard

    Thanks very much for that link. An interesting project and I wish them well.

    Plastics in the oceans cause massive problems for whales, turtles, fish and birds – it’s by no means a minor concern. At one stage in our shark work we did 3 years of counting marine litter on the west coast of the UK, and if I didn’t understand the scale of the problem before, then I did afterwards.

    Plymouth University have been doing some research taking core samples from sediments from around the UK, and recently reported that they have found microscopic pieces of plastics in every sample – which means that it’s likely that plastic is now a part of the food chain, too, with who knows what consequences – scary stuff!

    Best wishes


  • RDE Jun 23, 2013, 10:45 am

    Hi Colin,
    I’m also interested in the second project on their agenda: Taking temperature and salinity gradient samples in portions of the high Arctic and Northwest Passage that are currently incompletely mapped. My nephew is a cold climate geophysicist who has done extensive research on Baffin Island. Since much of accelerated iceberg and glacier tail melt evidently takes place from below, this is critical data for understanding the pace of ice loss and its impact on future climate.

    Considering the extensive high latitude experience of many of the contributors to this forum, there may be some who wish to become involved in this project and thus expand its scope.

    • Colin Speedie Jun 23, 2013, 3:04 pm

      Hi Richard

      I’d agree that the glacier project is an interesting one, and I’ll be following their progress.

      Incidentally, there’s a link on their site to which is well worth visiting.

      And a really good high latitude sailing project can be viewed by searching for Tara Expeditions.

      All good stuff….

      Best wishes


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