Interception
A bloom is a moving body of organic material inside a moving body of water. Every design decision here follows from that one awkward fact.
The patch you needed on Tuesday is four kilometres downwind by Thursday, sitting eight metres lower than it was, over ground the survey launch cannot reach. Nothing bolted to a jetty solves that. So the treatment stage travels.
Gas handling, bubble generation, the oxidant stage and the delivery array all ride the same hull and go to the water. That premise belongs to the SeaBreather platform, which explains the vessel side of it properly. HABslayer is what the platform does when the thing in the water is alive, multiplying and possibly toxic.
A bloom is not a dead zone with a colour
Hypoxia is an absence. Something took the oxygen and nothing gave it back. A bloom is the opposite kind of problem: there is too much of something, that something has a chemistry, and in many species it carries a toxin into shellfish tissue and, for Karenia, into the air above the surf.
Which makes interception two duties running at once. An oxidant duty acts on the organic material. An oxygen duty holds the water underneath it up, because bloom material that dies decomposes, and decomposition is exactly how a bloom becomes a fish kill three days after everyone declared it over.
Get the first without the second and you have swapped a bloom for a crash. That is the whole reason this is a mode of an oxygenation platform rather than a boat with an algaecide tank on the back.
The chain, in order
- Locate Ocean-colour and hyperspectral products narrow the search box; a boat confirms what is in it. Imagery is good at telling you where to look and bad at telling you what to do when you get there.
- Read the patch Species, cell count, vertical distribution, temperature, salinity, pH, dissolved oxygen, and the background organic material that will absorb oxidant to no purpose. Karenia in a shallow warm bay and Pseudo-nitzschia on an upwelling coast get different plans.
- Set the ceiling before the dose Oxidant concentration and contact time are capped at the site limit rather than at what the plant can produce. This step is the one an inspector will reconstruct from the log, so it is written down before the vessel moves.
- Deliver where the cells are Some patches float. Some sit in a subsurface maximum ten metres down, invisible from the quay and untouched by anything working the surface.
- Put the oxygen back Nanobubble oxygen through the treated column, so that what has been knocked down does not consume the water on its way out.
- Assay, then adjust Counts and toxin assays either side of the pass, at depth, feeding the next tasking rather than a document written in November.
Deep Strike, in plain terms
Deep Strike runs the same chain on water that is not yours yet. A patch forming in the next bay gets worked before wind and tide deliver it.
Three things make that worth paying for. A forming patch is smaller, shallower and less concentrated than the same bloom four days on, so the gas budget goes further. A tasking is cheaper to run than an incident, because an incident carries lawyers, press officers and overtime. And a ministry that announces nothing has had a better week than one announcing a closure.
Adjacent Deep Strikes sit inside the base subscription for exactly that reason.
The seawater constraint that shapes everything else
Bromide is abundant in seawater and ozone goes after it about eighty-three times more readily than it goes after chloride. The hypobromite that comes out of that reaction can carry on to bromate, and bromate is a regulated substance, not a footnote.
The published controls are dull and effective: cap concentration, cap contact time, watch pH and temperature. The same literature is candid that capping them costs disinfection efficiency, so there is a genuine trade-off to operate — per site, against a measured background, with the log open.
Any supplier who tells a Gulf utility that ozonating its seawater is consequence-free has either not read this literature or is hoping the utility has not.
What actually does the knockdown
There is an unresolved argument in the literature about whether nanobubbles themselves produce hydroxyl radicals. Moleaer and Arizona State University reported reactive oxygen species, radicals included, from injected nanobubbles in 2020. Chae, Kim, Kim and Fortner, testing under controlled ambient conditions and publishing in ACS ES&T Engineering in 2023, found that generation minimal at best.
For a platform vendor that is an interesting disagreement. For a bloom operator it is a dosing decision, and the two positions do not cost the same. If radicals were quietly contributing, a lower oxidant dose would still clear a patch and the margin would carry you through a bad site. If they are not, the result is governed by oxidant, contact time and how much organic background is eating your dose before it reaches a cell.
We plan for the second case. A dose plan built on a mechanism that may not be there is a plan that under-delivers on the one day it is being watched.
Controls and data
Every dose is a decision, and every decision leaves a record.
Bloom work generates evidence whether you plan for it or not. Better to design the evidence than to assemble it afterwards from memory.
Alarivean's stated control philosophy is that oxygen and ozone application is tuned against measured parameters rather than run to a fixed recipe. On bloom material that is not refinement. It is the line between a treatment and an incident of your own making.
Where to look
Ocean colour and hyperspectral imagery bound the search area days ahead of a shore sample. Detection and forecasting get proper treatment on HABscan.
What is down there
Vertical profiles either side of each pass, plus counts and toxin assay. The number that matters is rarely the one you can take from the quay.
Where to be tomorrow
Forecast risk across the zone, so a Deep Strike reaches water that is still forming instead of chasing a patch that has already done its damage.
What the ministry gets
Position, time, method, dose and result, pass by pass, in a format a technical reviewer can check rather than a newsletter can quote.
The pillar under the log
Who else is watching the dose.
Bloom work is a public health operation dressed as a boat job. Counts move, a dose gets chosen, an advisory is held or lifted, and each of those decisions lands on people who were nowhere near the room. Which is the argument for putting the qualified sceptics inside the programme rather than downstream of its reports.
Alarivean insists on it. Local scientific institutions — a university marine laboratory, the fisheries institute, the health authority's own analysts — are engaged for the duration and sit on every water-quality feed the duty crew reads, from before the first pass until after the last. Bringing their own instruments is encouraged. More sensors beats more assurances every time.
What does it change? What happens on a bad day. The pass that misses, the patch that rebounds overnight, the assay nobody expected — those are the moments when a single-source record stops being evidence and becomes a question of trust. Nothing about bloom season should rest on trusting the contractor.
The three parts most programmes skip
Continuous. Not an induction in May and a slide deck in November. Present through the weeks when the decisions are actually being taken.
Raw, not digested. The telemetry as it arrives, not a summary we wrote afterwards. Those are different artefacts and only one of them is checkable.
Held somewhere else too. A season's record that exists solely on our servers is a record nobody can audit without our permission. Health and safety first means the data has more than one home.
Questions we get asked
Straight answers
Why treat the bloom at all, if the real problem is nutrient loading on land?
Because the two run on different clocks. Cutting nutrient loads is the durable answer and it arrives over decades. A bloom shuts an intake, a beach or a farm inside a fortnight.
Treating the water protects the years in between. It excuses nobody from the catchment work, and we would not want a fisheries directorate quoting us as though it did.
Does killing the cells release the toxin they were carrying?
Ask it, and ask it of everyone in this category. Any treatment acting on bloom cells has to answer for what those cells were holding, and a falling cell count is a weak way to check.
Assay sits in the operating procedure here rather than in an appendix to it. What nobody can currently hand you is a published open-water figure for the effect. Ours included.
What actually does the knockdown — the oxidant, or the bubbles?
We plan on the oxidant, deliberately.
Whether nanobubbles generate hydroxyl radicals on their own is contested: Moleaer and Arizona State University reported reactive oxygen species in 2020, and a controlled 2023 study by Chae and colleagues found that generation minimal at ambient conditions, if it happened at all. A dose plan that quietly relies on the optimistic reading is a plan that fails on a hard site.
Reference: Chae, Kim, Kim & Fortner (2023) in ACS ES&T Engineering
Will ozone in our seawater make bromate?
It can, and in Gulf and Red Sea water it is the binding constraint rather than a caveat. Ozone attacks bromide far faster than chloride, and the hypobromite that results can carry on to bromate.
Concentration and contact time are held to a site limit, pH and temperature are watched, and the disinfection efficiency lost to that ceiling is accepted openly rather than quietly recovered by dosing higher.
Source: Ozone: Science & Engineering — bromate in seawater ozonation
Has NOAA tested this?
NOAA's coastal science centres put an ozone nanobubble aeration system through an eight-acre pond trial near Fort Myers Beach in 2018. Algae were eliminated inside two days, reoxygenation held, and no harm to aquatic life was apparent.
Different equipment, different partners, a pond rather than a bay. It tells you the approach is sound at that scale. It tells you nothing about our hull at ours, and we will not blur the two.
Source: NOAA NCCOS, September 2018
How big an area can one vessel cover?
It depends on the patch, its depth, the organic background, the vessel tier and how much of the season is contracted.
That answer gets built against your bathymetry and your own bloom record during the site read, then tested on your water in a calibration phase. A single confident sentence on a website would be a guess dressed as a specification.
Next step
Bring us a species and a season.
Historic counts, depth profiles, the months it comes back in, whatever you have already tried. Alarivean reads that against the water and says whether this is the right instrument — including when it plainly is not.