What is Nannochloropsis Gaditana

Nannochloropsis gaditana is a species of marine microalga in the class Eustigmatophyceae, notable for producing one of the highest concentrations of EPA (eicosapentaenoic acid) found in any photosynthetic organism. It is the species behind most phytoplankton-based omega-3 supplements on the UK market, though you would not always know that from the label.

The name matters because "marine phytoplankton" covers thousands of species with wildly different nutrient profiles. Knowing you are taking N. gaditana specifically tells you something precise about what is in your supplement. Not knowing leaves you relying on a category term that could mean almost anything.

The biology is genuinely interesting. The marketing mythology built around it is often less so.

Taxonomy and Classification of Nannochloropsis Gaditana

What Makes Eustigmatophytes Distinctive

Nannochloropsis gaditana belongs to the class Eustigmatophyceae, a small group of microalgae whose defining characteristic is unusually high lipid accumulation. Where most photosynthetic microorganisms direct energy primarily into growth and reproduction, eustigmatophytes channel a substantial proportion into fat storage, particularly long-chain polyunsaturated fatty acids. When we first assessed this genus for supplement formulation, the lipid figures were what held our attention.

This is a taxonomic trait, not something introduced during cultivation or processing. When you see EPA figures on a Nannochloropsis product, you are looking at the organism's evolved biochemistry. We did not engineer this EPA capacity; we selected a species that already had it. The lipid content is the reason this genus attracted commercial interest in the first place, initially for biofuel research and later for human nutrition.

How N. gaditana Was Identified and Named

The species was first described by Lubian in 1982, isolated from the salt marshes near Cadiz in southern Spain. The epithet "gaditana" comes from the Latin name for Cadiz: Gades. It was originally grouped with other small green-looking microalgae before molecular analysis confirmed it as a distinct eustigmatophyte species.

Within the genus Nannochloropsis, six species are currently recognised: N. gaditana, N. oculata, N. oceanica, N. salina, N. granulata, and N. limnetica (the only freshwater member). All are characterised by small cell size, typically 2-5 micrometres, and high lipid content, but they differ in fatty acid composition, growth rate, and response to cultivation conditions.

We evaluated three of these species before settling on N. gaditana for ULTANA, primarily because of its EPA yield under the cultivation parameters we use.

EPA and Fatty Acid Composition of Nannochloropsis Gaditana

Why EPA Concentration Matters for Plant-Based Omega-3

The defining nutritional characteristic of N. gaditana is its EPA content. Published analyses report EPA at roughly 25-35% of total fatty acids, depending on growth conditions (Ma et al., 2016). In our own batch testing, we see figures consistently in the upper part of that range when cultivation parameters are tightly held. That proportion is higher than most commercially cultivated microalgae species and substantially higher than any terrestrial plant source.

This matters because EPA is one of two long-chain omega-3 fatty acids (the other being DHA) that your body uses directly. The alternative route, converting shorter-chain ALA from flaxseed or walnuts, is inefficient: published estimates put conversion at roughly 5-10%, varying by individual genetics and dietary context (Brenna et al., 2009). If you are relying on ALA conversion alone for your EPA, most of it never arrives.

EPA and DHA contribute to the normal function of the heart at a combined daily intake of 250 mg. This is an EFSA-authorised health claim under Commission Regulation (EU) No 432/2012.

Other Nutrients in Nannochloropsis Gaditana Biomass

Beyond EPA, the whole-cell biomass contains chlorophyll, violaxanthin and other carotenoid pigments, a range of amino acids, and various micronutrients. Open a tub of dried N. gaditana powder and the colour is a deep olive-green, noticeably darker than spirulina. The carotenoid profile is distinctive: violaxanthin is the dominant pigment, unlike the beta-carotene or astaxanthin emphasis you find in other algae species.

These additional nutrients carry over into supplements made from intact dried biomass. If you are taking an extracted algae oil rather than a whole-cell product, you get primarily the fatty acids and lose most of this broader nutrient matrix.

We chose whole-cell delivery for ULTANA partly for this reason: you keep the EPA and the supporting pigments and micronutrients alongside it. That is a trade-off worth understanding when comparing product formats.

One important caveat: N. gaditana does not produce meaningful DHA. If you are building a plant-based omega-3 strategy, phytoplankton covers EPA and a dedicated Schizochytrium-derived supplement covers DHA. We manufacture both because no single species currently provides adequate amounts of both.

You may also find websites claiming Nannochloropsis contains "over 65 trace minerals." We have reviewed the published analytical data and it does not support these claims. What the organism provides is a genuinely EPA-rich matrix with a solid supporting nutrient profile. That is a strong enough case without the embellishment.

How Nannochloropsis Gaditana Differs from Other Nannochloropsis Species

All six Nannochloropsis species produce EPA, but they are not interchangeable. When we reviewed the published lipid data across the genus, the differences in fatty acid proportion, growth behaviour, and research history were large enough to matter when you are evaluating what is inside a supplement.

N. gaditana vs N. oculata in Supplement Use

N. oculata has the longest commercial history in the genus, primarily as a feed organism in aquaculture hatcheries. It is well-characterised and widely available, but its EPA proportion as a percentage of total fatty acids is generally lower than N. gaditana under comparable growth conditions (Zanella and Vianello, 2020).

If your supplement names N. oculata rather than N. gaditana, you are still getting an EPA-producing organism. The difference is in concentration, not category. Whether that difference matters to you depends on the quantified EPA per serving on the label, which is the number worth comparing regardless of species.

N. gaditana vs N. oceanica for Human Nutrition

N. oceanica has become the most studied species in the genus for genetic and metabolic engineering research. Its genome was the first in the genus to be fully sequenced, and it is the preferred organism for researchers trying to enhance lipid production through gene editing.

For current supplement use, the practical distinction is that N. oceanica appears more often in research contexts than in consumer products. N. gaditana has a more established track record in commercial-scale cultivation for human nutrition. If you see N. oceanica on a supplement label, the EPA production biology is similar, but the production and quality control infrastructure around it is less mature for food-grade applications.

How Nannochloropsis Gaditana Is Cultivated for Supplements

Photobioreactor Cultivation and Nannochloropsis Nutrient Consistency

Closed photobioreactors are sealed glass or plastic tube systems where light, temperature, water quality, and nutrient delivery are all controlled. Walk into the facility and what you notice first is the tubing: long runs of clear tubes with green culture circulating under artificial light. The algae grow in a protected environment, isolated from atmospheric contaminants, competing organisms, and variable weather.

For N. gaditana specifically, controlled conditions matter because the fatty acid profile responds to environmental variables. Light intensity, nitrogen availability, and temperature all influence how much EPA the cells produce relative to other lipids. In our photobioreactors, we hold these variables within defined ranges, which is why batch-to-batch consistency in EPA content is achievable. In an open pond, it is not.

Open-pond cultivation is cheaper: large, shallow outdoor pools exposed to the surrounding environment. The trade-off is contamination risk and seasonal variation in nutrient output. If you are comparing two phytoplankton supplements and one costs noticeably less, the cultivation method is usually the reason.

Reading a Nannochloropsis Gaditana Supplement Label

If you are standing in a health shop or comparing products online, three details separate a supplement you can evaluate from one you have to take on faith.

Species binomial on the label. A product that says "marine phytoplankton" without naming Nannochloropsis gaditana (or another specific species) is asking you to trust a category term. You cannot look up research, compare nutrient profiles, or verify claims against published data without the species name. If the manufacturer will not tell you what organism is in the product, that silence tells you something.

Quantified EPA per serving. Look for milligrams on the nutritional information panel, not adjectives like "omega-3 rich" or "nutrient dense." Your body responds to dose, not to marketing language. Without a declared EPA figure, you cannot compare the product to anything else on the shelf or assess whether it contributes meaningfully to the 250 mg daily threshold referenced in the EFSA heart health claim.

Cultivation disclosure. Closed photobioreactor or open pond? If the product page or packaging does not say, ask. We state our method on every product page because we consider it a genuine differentiator. Silence on this point from other producers is worth noticing.

What Cultivating Nannochloropsis Taught Us

Growing N. gaditana at production scale teaches you things that published literature only partially captures. These are observations from our photobioreactor facility that shaped how we formulate and what we look for in competing products.

Not all N. gaditana cultures produce the same EPA. Strain-level variation within the species is real. We have tested cultures from different culture collections and seen EPA yield differ by as much as 15% under identical growth conditions. The strain you start with matters as much as how you grow it. If a producer names the species but not their strain source, you are missing a variable.

Light cycles and temperature shift the lipid profile batch to batch. We can observe this directly in our certificate-of-analysis data. A two-degree temperature change during the growth phase alters the ratio of EPA to other fatty acids. Tighter environmental control means more predictable EPA per gram. This is why photobioreactor consistency is not just a purity argument. It is a dosing argument.

We chose N. gaditana over N. oculata and N. oceanica for a specific reason. During formulation development, we ran fatty acid profiles on all three species grown under our standard parameters. N. gaditana consistently delivered the highest EPA as a proportion of total lipids. The margin was large enough that the species choice was straightforward, not marginal.

Open-pond contamination is not a theoretical risk. We have reviewed certificate-of-analysis data from open-pond producers and seen heavy metal readings that would fail our incoming-material specification. Arsenic and lead are the usual concerns. Closed-system cultivation does not eliminate testing, but it changes what you find when you test.

Whole-cell delivery keeps nutrients that extraction discards. When you extract oil from N. gaditana, you isolate the fatty acids but lose the chlorophyll, carotenoids, and amino acid matrix. We chose whole-cell powder because the supporting nutrients have value. If your priority is EPA alone, extracted oil works. If you want what the whole organism provides, the format decision matters.

Nannochloropsis Gaditana FAQ

Is Nannochloropsis gaditana safe to take as a daily supplement?

N. gaditana has an established history of use in aquaculture nutrition and is consumed as a food-grade supplement. In our experience formulating with this species, it is well-tolerated at standard supplement doses.

The one group who should check with their GP first: anyone on blood-thinning medication. EPA can have mild anticoagulant effects at high combined intakes (generally above 2-3 g of EPA plus DHA daily). A typical phytoplankton capsule delivers well below that threshold, but your GP needs to know everything you are taking.

How is Nannochloropsis gaditana different from chlorella and spirulina?

The key difference is the fatty acid profile. Chlorella is a freshwater green alga valued for protein and chlorophyll but producing no meaningful EPA. Spirulina is a cyanobacterium, not a eukaryotic alga, and is similarly protein-focused with no long-chain omega-3 production.

We manufacture all three because they serve different purposes: chlorella for its protein and chlorophyll, phytoplankton for EPA. The three are routinely shelved together under "algae" in health shops despite having substantially different nutritional roles.

Can Nannochloropsis gaditana replace fish oil for omega-3?

It can replace the EPA component of fish oil. It cannot replace the DHA component. If your current fish oil provides both EPA and DHA, switching to N. gaditana alone would leave a DHA gap. This is exactly why we developed a separate algae-derived DHA supplement alongside the phytoplankton range: together, they cover both long-chain omega-3s from plant sources without the fish.

Does Nannochloropsis gaditana taste like fish?

No. Whole-cell phytoplankton has a mild, slightly vegetal flavour, closer to a seaweed cracker than anything fishy. Fish oil develops its characteristic strong taste through oxidation during processing and storage. We hear regularly from customers who switched specifically because of the reflux that fish oil capsules sometimes cause. If taste has put you off omega-3 supplements before, this is a different experience.

What dose of Nannochloropsis gaditana should you take?

Dosing depends on the EPA concentration per serving in your specific product, which is why we put the milligram figure on every ULTANA label. The EFSA-authorised heart health claim applies at a combined 250 mg of EPA and DHA daily.

Check the nutritional information panel for the actual EPA content per dose, then work out whether you are meeting that threshold from phytoplankton alone or in combination with other omega-3 sources. If a product does not declare EPA in milligrams, you simply cannot do this calculation.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Consult your GP before starting any supplement.

Methodology and Disclosure

Phytality manufactures supplements from Nannochloropsis gaditana grown in closed photobioreactors. We have a direct commercial interest in this species. Taxonomic descriptions reflect published biology. EPA concentration ranges are drawn from Ma et al. (2016) and Zanella and Vianello (2020). ALA conversion estimates are from Brenna et al. (2009).

The EFSA-authorised health claim for EPA and DHA is cited under Regulation EU 432/2012 with its intake condition stated. Species comparisons within the Nannochloropsis genus reflect published compositional analyses. Where we describe our own cultivation method and heavy metal comparisons, this reflects our production and formulation process, not independent third-party testing.

Claim types used: category-level facts (established microalgae biology), ingredient-level facts (species-specific EPA data, cited), product-specific facts (Phytality cultivation method), one EFSA-authorised health claim (heart function, Regulation EU 432/2012), and editorial comparisons (genus-level species distinctions, label-reading guidance).

Last reviewed: March 2026. Next review due: March 2027.