Ten problems, one body of water.
Seven stressors we are asked about, and three ledgers that end up paying for them. Some of these answer to a vessel. Some do not, and this page says which.
How this page is arranged
The water does not keep its problems apart, so neither will we.
Until recently each of these had a page to itself. Seven of those pages said nearly the same thing in slightly different words, and three of them leaned on a reference that turned out not to exist anywhere an academic index could find it. That was not a formatting problem. It was an evidence problem, and consolidating the pages was the smaller half of fixing it.
What follows runs in causal order rather than alphabetical. Oxygen first, because it is the deficit that ends things; then the bloom that consumes it; then the nutrient load underneath both; then four questions about contamination that get asked in every first meeting. After that, three sections about who carries the cost while the argument goes on.
Every figure below links to the body that published it. Where the only available source is press reporting rather than the study itself, the sentence says so.
Stressors
01 — Dead zones
Oxygen missing from the layer that lost it. The duty the fleet was built around.
02 — Harmful algae
A deadline rather than a condition. What you buy is being in the water in the right week.
03 — Nutrient loading
The cause, arriving from land, on a clock measured in decades.
04 — Harmful emissions
Where the old site claimed most and we can support least. Four figures withdrawn.
05 — Microbial consortia
Organisms inside a volume you can define, which is a narrower promise than it used to be.
06 — Plastic leachates
Withdrawn. Nothing supports a chemistry claim here and we are not writing around it.
07 — Heavy metals
Neutralised, not dropped to the bottom. Our own account, labelled as ours.
Who carries it
08 — Public health
One guideline value is not a threshold, and the notice is signed by somebody who does not work here.
09 — Marine life
Not a beneficiary category. The instrument that tells you whether the water changed.
10 — Blue economy
Two and a half decades of growth measured in output, with no series for the condition of the input.
01 — Dead zones
Oxygen is the deficit that arrives on a calendar.
Hypoxia is seasonal, it is driven by heat and stratification, and it forms in the part of the water column that surface aeration never reaches.
NOAA sets the hypoxic line at 2 mg/L of dissolved oxygen. That number is a definition, not a target: a review of sensitive species in the Delaware estuary put the lethal-level requirement between 4 and 6.4 mg/L, with roughly 5 mg/L adequate for many of them. Water at 2.5 mg/L is not hypoxic by the definition and is still killing things.
The scale gets measured every summer, and 2025 was a comparatively good year in the Gulf of Mexico: 4,402 square miles, the fifteenth smallest in thirty-nine years of records. That is what a good year looks like. Worldwide, Diaz and Rosenberg counted more than 400 coastal dead zones in 2008, with the count roughly doubling every decade since the 1960s.
This is the duty the vessels were built around, and it is the one we are most comfortable being measured on: oxygen delivered into the layer that lost it, held for a season, with the readings going to somebody outside this company at the same moment they reach our crew. What it is not is a change to the load that caused the deficit. That is section three.
02 — Harmful algae
A bloom is a deadline with a colour.
Every other stressor on this page can be worked on in your own time. This one cannot. Cells double, wind pushes the patch, and the difference between a treated week and an untreated one is decided before most procurement departments have opened a file.
So what an operator is actually selling against algae is not a machine. It is presence — hulls already inside a service zone, gases already contracted, crews already accredited to that regulator, so that the response to a forecast is a course change rather than a mobilisation. Blooms in the water next door get intercepted under the same arrangement, because a patch four miles away is your patch in two days.
The cells are the visible half. The toxin is the half that closes a beach after the water has gone clear again, which is why the measurement obligation runs on the toxin assay rather than on cell counts. HABslayer carries the oxidant duty; HABscan covers what a satellite can and cannot tell you about where the patch goes next.
03 — Nutrient loading
The right answer to this one takes twenty years, and it should still be started.
Nothing a vessel does reduces the nitrogen and phosphorus arriving from a catchment. We are not a nutrient programme and we will not be sold as one.
The Baltic is the case that settles the argument in both directions. Nine countries agreed reductions, delivered a large part of them, and had them audited: against the 1997–2003 reference period, normalised nitrogen input was down 11 per cent by 2022 and phosphorus down 32 per cent. Real work, honestly measured. The Baltic Proper and the Gulf of Finland still failed their maximum allowable input for both nutrients, and the hypoxic area of that sea has gone from under 10,000 square kilometres before 1950 to more than 60,000 since 2000.
Read that as an argument against catchment work and you have read it backwards. It is an argument about lag. Nutrient already in a system keeps cycling long after the tap is turned down, so the years between the policy and the recovery are years somebody has to get through with the water they have.
That gap is the only honest place for in-water treatment to stand. It buys seasons inside a defined zone while the catchment answer works — and the moment anyone describes it as a substitute for that answer, including anyone selling it, the Baltic numbers are the reply. HAB Control sets out how the two clocks are written into a strategy without either one overstating itself.
04 — Harmful emissions
This is the section where the old site said the most and we can support the least.
Four figures used to sit here. A share of atmospheric warming attributed to methane from blooms. A warming potency multiple for nitrous oxide. A headline about climate costs of up to twenty-four trillion dollars that better nutrient management would avoid. A methane and nitrous oxide emission rate for Lake Erie, expressed as half a million tonnes of carbon dioxide equivalent a year.
Not one of them could be traced to a body that published it. So they are gone, and nothing has been put in their place, because the honest replacement for an unsupported number is not a smaller unsupported number.
What is on the record in adjacent chemistry is worth stating plainly, and it is not a claim about our equipment. NOAA reports ocean acidity up roughly 30 per cent since the start of the Industrial Revolution, about 0.1 of a pH unit, and projects an end-of-century pH the oceans have not experienced in more than twenty million years. Aragonite saturation has fallen by about a fifth across much of the surface ocean. Above a saturation state of 3, shell-forming life is more likely to survive and reproduce; below 1, aragonite shells begin to dissolve.
The question a buyer should ask us instead
We inject industrial gases from vessels that burn fuel to get to the zone. That is a footprint, it belongs on our side of the ledger, and a serious counterparty should ask for it during the site read rather than discovering it later.
What we will not do is convert any of this into a carbon claim. Alarivean does not issue credits, does not sell an offset, and does not describe a programme as climate finance. If a treated zone ever turns out to have a measurable greenhouse gas benefit, the measurement has to be somebody else's before it is anybody's revenue — which is the whole argument behind Credible Exchange.
05 — Microbial consortia
Organisms inside a volume somebody can draw a line around.
The retired page said that oxygen and ozone nanobubbles neutralise biohazards and precipitate pollutants out of solution, and cited a 2020 paper for it. That paper could not be found in any index we searched. The claim went with it.
What replaces it is narrower and much better attested. Organisms held in a bounded volume — a ballast tank, a quarantined basin, a treatment train — respond to a controlled oxidant duty, and the response has been measured by people who are not us. NCCOS-affiliated testing in 2020 evaluated a commercial nanobubble ozone system on ballast water and found it effective against algae, bacteria and motile zooplankton, with no statistically significant adverse residual toxicity in the receiving water.
Two warnings sit on that sentence. The equipment tested was another company's, and its name abbreviates to the same four letters as ours, which makes a skim-reader's mistake very easy to make; the evidence page sets the collision out in full. Open water is also not a bounded volume. Dilution beats chemistry there, which is why this duty is priced against tanks and enclosed basins and not against a bay.
The regulatory frame is the IMO's ballast water convention, in force since 8 September 2017, with a discharge standard of fewer than ten viable organisms per cubic metre at 50 micrometres and above. ChemSlayer is where that duty lives in this network.
06 — Plastic leachates
We are taking this one down rather than rewriting it.
Three pages of the old site shared a near-identical block of text and one reference. Plastics was one of the three. Nothing in our fact bank supports a claim that this treatment degrades plastic or neutralises what leaches out of it, and there is no smaller version of that claim worth making.
The only adjacent thing we do is physical. Floating and shoreline material inside a contracted service zone can be recovered under the Beach Cleanse augment, scoped in writing before anyone quotes it. That is a recovery duty with a workboat and a crew. It is not chemistry, and describing it as chemistry is how this section got into trouble the first time.
If plastic is the primary problem in your water, we are the wrong call. Saying that here costs us a handful of enquiries. Saying it in month four of a programme would cost considerably more, and it would be deserved.
07 — Heavy metals and inorganic toxins
Neutralised, rather than dropped to the bottom.
The old page said this technology precipitates nitrogen, phosphorus and inorganic metals out of solution. It has been withdrawn, and not only for want of a source.
Precipitation is a relocation. A metal that leaves the water column and settles into sediment has not stopped being a metal; it has become a dredging problem, a benthic problem and, in a shallow basin, a problem that comes back the next time a storm or a propeller stirs the bed. Any supplier offering you precipitation as an outcome should be asked what happens to the sediment afterwards.
What we put in its place rests on a research agreement rather than a paper. Work carried out with the NOAA scientist Dr Peter Moeller, under a Cooperative Research and Development Agreement held by this company, found the treatment neutralises inorganic toxins instead of precipitating them: the toxicity is disabled where the material already sits, in the water, rather than relocated to the bed.
Three qualifications belong in the same breath. The agreement is a private instrument and was never published, which is ordinary for a CRADA and is why searching for it returns nothing. A research agreement is not an endorsement, and NOAA does not endorse commercial products. And this is our account of our own work, which puts it in the weakest tier of everything on this site — the evidence page sorts the tiers and says so there too.
08 — Public health
A health authority should never have to take our word for a reading.
Two figures used to sit in this position. One said that around sixty-five per cent of American estuaries and coastal waters are moderately to severely degraded, attributed to NOAA. The other put Lake Erie property-value losses at eleven billion dollars. Neither could be traced to the body it was credited to, and both are gone.
The documented version is smaller and more useful. In August 2014 a bloom on Lake Erie reached Toledo's intake and roughly half a million residents were advised not to drink the tap water; the same source puts the shoreline property-value loss from that event at $10.05 million, three orders of magnitude below the number this site used to print.
Guideline values are where the real damage gets done, because there is rarely just one. WHO publishes three for total microcystins — 1 microgram per litre for lifetime drinking-water exposure, 12 for short-term, 24 for recreational water. Quote only the first and a directorate ends up issuing a do-not-drink notice in circumstances WHO's own guidance does not call for. Quote only the last and the opposite happens.
The rest is exposure that does not read on an intake meter at all. Aerosolised brevetoxin from red tide produces an upper-respiratory syndrome, and asthmatic subjects in one study reported symptoms up to at least five days after a single hour of exposure. Domoic acid has no antidote and is not destroyed by cooking or freezing.
Why oversight is a pillar rather than a paragraph
A supplier holding the only instruments, the only data and the only report has handed a public-health authority a story it cannot audit. We build every programme the other way. Relevant local scientific institutions are engaged from the situation report onward, with access to every water-quality feed our own crews steer by, live, plus anything else they care to bring.
The point is the second copy of the record. If our targets and the health of the water ever pull against each other, somebody outside this company already has the readings to say so, without asking us for them first.
09 — Marine life
Not a category of beneficiary. The instrument that tells you whether anything changed.
Biology is the only reading that cannot be produced by our own equipment, which is exactly why it is the one worth contracting somebody else to take.
What a kill event looks like in a record: Kuwait Bay, August and September 2001, more than 2,500 tonnes of wild mullet, roughly a hundred times the size of a red-tide-linked kill two years earlier. The peer-reviewed account attributes it to bacterial disease, harmful algae and eutrophication acting together — three of the headings on this page, in one bay, in one month.
Reefs carry their own scale. Between January 2023 and March 2025 bleaching-level heat stress reached 84 per cent of the world's reef area across 82 countries, the fourth and largest global bleaching event on record. The monitoring network's 2020 assessment had already put the loss at about 14 per cent of the world's coral since 2009.
And the stock in the water is now mostly farmed: aquaculture reached 94.4 million tonnes of aquatic animals in 2022 against 92.3 million from capture, the first year it went ahead. Half the world's aquatic protein is grown in water that somebody has to keep alive on purpose. ReefHealer covers the reef duty and its limits.
10 — Blue economy
Measured in output for thirty years, and never once in the condition of the input.
The OECD puts the ocean economy at US$2.6 trillion of gross value added in 2020, double its 1995 figure in real terms and compounding at 2.8 per cent a year — fifth place, if you entered it in the table of national economies. Marine and coastal tourism is projected to be its biggest single sector by 2030, at US$777 billion and more than 8.5 million jobs.
Read the series and you will not find a line for whether the water was in good condition while all that value was produced. Nobody is hiding it. It has simply never been an entry, which is why the cost of a bad season shows up scattered across cancellations, membrane replacement, throttled output and closed harvests, and never under a heading anyone budgets against in advance.
A previous version of this page valued ocean goods and services at $2.5 trillion a year and credited the World Bank. We could not verify that figure and it is not here. Marine Prosperity makes the institutional version of this argument; AquaProsper makes the operator's version, for a finance director who already carries the exposure under another name.
Where the stressor becomes a place
Three water types, and the difference between them is time.
The same deficit behaves differently depending on how long the water stays put. That single variable changes the treatment, the owner, the regulator and the price, which is why the argument splits three ways from here.
Questions this page usually provokes
Three that arrive by return
Why were the separate stressor pages removed?
Seven of them repeated one paragraph under different headings, and three rested on a citation nobody has been able to locate in any academic index.
The stressors are real and they arrive together, so they are argued together now. Every old address redirects to the section that replaced it, and each of those sections says what was taken out.
Does the treatment work on plastics or plastic leachates?
We make no claim that it does. If plastic is the primary problem in your water, an Alarivean programme is the wrong instrument, and that answer will not change during a procurement.
What can you actually say about heavy metals?
That inorganic toxins are neutralised rather than precipitated out of solution, and that this comes from work under our research agreement with NOAA rather than from a published paper.
It is our own account of our own work. That places it in the weakest evidence tier we operate, and we would rather label it that way than have a reviewer do it for us.
Sources cited on this page
- NOAA NCCOS — Below-average summer 2025 dead zone measured in the Gulf, July 2025.
- NOAA NCCOS — Hypoxia research programme.
- Delaware River Basin Commission — Review of dissolved oxygen requirements of key sensitive species, November 2018.
- VIMS — Chesapeake Bay dead zone report, December 2025.
- Diaz & Rosenberg, Science — More than 400 dead zones worldwide, 2008.
- NOAA Fisheries — The untold story of harmful algal blooms.
- Alvarez et al., via Newsweek — Florida's losses from red tide, January 2024.
- Reviews in Aquaculture — Global fish-killing harmful algal blooms, 2024.
- HELCOM — Inputs of nutrients to the Baltic Sea, indicator update 2025.
- Hypoxia in the Baltic Sea: biogeochemical cycles, benthic fauna and management, 2014.
- NOAA PMEL — What is ocean acidification?
- NOAA Ocean Acidification Program — Acidification is more pervasive than previously thought.
- NOAA NCCOS — Nanobubble ozone technology and ballast water invasive species, July 2020.
- IMO — Implementing the ballast water management convention.
- NOAA GLERL — Great Lakes Aquatic Nonindigenous Species Information System, 2019.
- WHO — Microcystins background document for drinking-water guidelines, 2020.
- Fleming et al., via PMC — Aerosolised red tide toxins and asthma.
- California Department of Public Health — Domoic acid fact sheet.
- Harmful Algae — The 2001 Kuwait Bay fish kill.
- NOAA and the International Coral Reef Initiative — The fourth global coral bleaching event, 2024–2025.
- UNEP / GCRMN — Status of coral reefs of the world 2020.
- FAO — The state of world fisheries and aquaculture 2024.
- OECD — The ocean economy to 2050, March 2025.
- OECD — The ocean economy in 2030, 2016.
One water body at a time
Which of these ten is actually yours?
Most people who write to us name two or three and turn out to have one. Send the water body, what goes wrong in it, which months, and what a bad season costs — we will tell you which heading it belongs under, including when the answer is that we are not the right instrument.