Deep Ocean Water & Seawater Concentrates

Take a hundred litres of open ocean and thirty-five hundred grams of it is dissolved salt. Pull the same sample from below the sunlit layer and something else changes: it stops being seasonal. Deep ocean water — anything taken below roughly two hundred metres, where sunlight no longer reaches — makes up close to ninety per cent of the ocean's volume and holds a temperature that barely moves from zero to three degrees across the globe. Nothing lives in it photosynthetically, nothing rains into it, and nothing in a warm harbour stirs through it. That constancy is the product.

Eata Marisource supplies that water and the streams made from it: chilled bulk deep seawater drawn from a documented depth, desalinated deep-sea water whose hardness and mineral balance are dialled to a number you specify, membrane concentrates enriched towards either monovalent or divalent ions, dried mineral solids that ship at ambient temperature, and chemically defined seawater blends for laboratory and corrosion work.

01 Depth Reads Like a Specification

Surface seawater has to be qualified every time you take it: plankton blooms move it, river plumes dilute it, storms resuspend sediment. Depth removes most of those variables at once. Published profiles describe four properties that hold from year to year at a well-chosen intake — a temperature that stays in single digits, a salinity pinned near 35, dissolved nitrate, phosphate and silicate accumulated from remineralisation of sinking material, and a microbial load far below that of any harbour or estuary draw.

Commercially worked sites document this well. At Hawaii's Natural Energy Laboratory, roughly 900 metres of depth is reached through an offshore cold-water pipe of about 2.7 kilometres. Japanese production is concentrated at Cape Muroto, where the shelf drops steeply and the water is drawn from several hundred metres; analyses quoted for that source put magnesium at 1,200–1,400 mg/L and calcium at 380–420 mg/L, an Mg/Ca ratio near three, with nitrate and silica enriched relative to the local surface layer. At Kumejima in Okinawa the intake sits around 612 metres and the desalinated product is adjusted to a hardness below ten — the same water, run through a membrane, serving a completely different end use.

02 The Ion Inventory You Are Actually Buying

Every specification that follows is a rearrangement of one list. Open ocean water at standard salinity carries roughly these concentrations, and deep ocean water carries them with the same proportionality — what changes at depth is biology and temperature, not the major ion proportions:

Two observations follow. Magnesium outruns calcium roughly three to one, which is unusual among natural waters and is why deep seawater mineral products skew magnesian. And the interesting elements sit four or five orders of magnitude below the majors — lithium at a fraction of a milligram per litre is the entire reason extraction economics depend on volume and selectivity rather than on concentration.

Coastal pumping infrastructure for a sub-surface seawater intake.

A single chilled seawater sample bottle, condensation beading on the outside of the glass.

03 Concentration: Turning 35 g/L into Something Shippable

Shipping bulk seawater anywhere is an exercise in moving water. Every process below exists to answer one question — do you want the water, the salt, or one particular family of ions:

Nanofiltration deserves a paragraph of its own because it is the hinge on which most deep-water plants turn. A single pass operated around twenty bar rejects monovalent ions weakly — sodium around five per cent, chloride near ten — while holding back sulfate at about ninety-eight per cent and magnesium at roughly three quarters. The permeate is therefore a softened, sulfate-lean water; the retentate is a magnesian, sulfate-rich concentrate. One intake becomes two catalogue lines, and the product split is chosen by membrane selection rather than by recipe. Electrodialysis goes further: fitted with monovalent-selective membranes it can push sodium chloride one way and magnesium the other, producing a Mg-enriched stream four to six times seawater that can be thrown down as hydroxide, while the sodium chloride side feeds either crystallisation or electrolysis. The route is commercial for seawater in Japan, Korea and Kuwait, and it costs more energy per tonne of salt than water-transport membranes — worth knowing before specifying it.

Pressure vessels and high-pressure pumps inside a seawater membrane plant.

A clamped membrane stack used to concentrate and split brine streams.

04 Grades and Forms We Supply

The last line deserves explaining, because it is often the most misunderstood. Natural seawater is chemically realistic but irreproducible — it drifts over days in a carboy. A defined blend built to the ASTM D1141 formulation weighs out sodium chloride at about 23.9 g per kilogram of solution, sodium sulfate near 4.0, potassium chloride 0.68, bicarbonate 0.20, bromide 0.10, boric acid 0.026 and fluoride 0.003, with magnesium and calcium added as hydrated chloride solutions. It deliberately omits organic matter and nutrients so that every batch behaves identically, which is exactly what immersion, alternate-immersion and crevice corrosion methods require. Formulations built for marine life are the opposite: they add carbonate buffering near pH 8.2 and trace iron, iodine, molybdenum and zinc, and those additives make them unusable as a corrosion electrolyte. Tell us which reproducibility problem you have and we will supply the right one.

05 What Each Downstream Actually Uses

• Cold-bed agriculture and OTEC: the temperature differential is the asset. Running chilled water through buried coils condenses atmospheric moisture at the root zone and lets temperate crops grow in the tropics — the technique behind decades of work at NELHA, where the same cold water also drives ocean-thermal power at pilot scale.
• Aquaculture and live feed: cold, pathogen-poor water with elevated silicate supports diatom-dominated cultures, live feeds and shellfish; hatcheries running intakes tens of metres down already report lower parasite pressure, and going deeper reduces variability further.
• Fermentation and culture media: the Mg-rich profile and absence of bloom-derived organics suit mineral-adjusted process water, and the hardness split tabulated above lets you specify soft one week and magnesian the next.
• Cosmetic water phase: the mineral balance is why formulators ask for it by name — the magnesium-forward profile, absence of bloom-derived organics and adjustable hardness let the same source serve several product lines.
• Mineral recovery research: beyond the majors, the concentrate is where lithium, strontium, rubidium and uranium sit at sub-milligram levels, and adsorbent-based recovery is under development precisely because single-product routes rarely pay for themselves.

Bulk containers and drums of liquid mineral concentrate staged for dispatch alongside a laboratory sample jar.

06 Certificates and Handling

Water is easy to characterise and easy to misrepresent, so we report the measurements rather than adjectives. Each lot ships with:

• full cation and anion panel by ICP-OES and ion chromatography — the numbers above plus whatever else you specify;
• total dissolved solids and conductivity, with salinity reported as a conductivity ratio against the standard seawater reference rather than as a standalone figure;
• intake depth and temperature at the time of pumping, because those two define everything else;
• turbidity, apparent colour and total viable count for anything destined for culture work;
• heavy metals down to specification limits, plus bromide and boron for cosmetic and beverage customers.

Handling is disciplined by the same logic that makes the water interesting. Bulk deep seawater ships chilled and should stay cold; concentrates tolerate ambient transport but will precipitate if the temperature swings, so we specify storage windows per grade and note the re-dissolution conditions on the drum. Dried solids are hygroscopic by nature and are packed accordingly.

An inductively coupled plasma spectrometer used to verify the elemental profile of each lot.

07 Tailored Water, Not Just Bottled Water

Most enquiries start backwards from a target rather than forwards from a catalogue. We can set a hardness value and hold it across lots, push the Mg/Ca ratio up or down by blending permeate and retentate, strip sulfate for a sensitive precipitation step, concentrate to a defined TDS so your crystalliser sees a known feed, or dry a specific ion profile into a powder that ships without refrigeration. Where a programme needs the major ions but none of the variability, we build the blend from reagent salts to a defined formulation instead of starting from ocean water — and we will tell you plainly when that is the better buy. Send us the ion numbers you need to hit, the matrix the water will sit in, and the analytical method your team trusts; the isolation route follows from there.

Eata Marisource moves these materials worldwide for research and industrial programmes. Request the current lot analysis, a sample drawn at the depth you intend to specify, or a quotation on a continuous campaign.

For Research or Industrial Raw Materials, Not For Personal Medical Use!