On July 21, 2026, our team conducted a marine survey bioblitz at Theotokos in South-east Pelion, Greece. The survey explored shallow rocky shores and nearshore habitats, recording fish, sponges, anemones, molluscs, echinoderms, crustaceans, algae, and coastal birds.

A total of 32 taxa were recorded during the survey, including 26 identified to the species level, 2 to the genus level, and 1 to the suborder level.

Fish

• Epinephelus marginatus (Dusky Grouper)
• Boops boops (Bogue)
• Coris julis (Mediterranean Rainbow Wrasse)
• Symphodus rostratus (Pointed-snout Wrasse)
• Atherina sp.
• Blennioidei (Blennies)
• Diplodus vulgaris (Common Two-banded Seabream)
• Apogon imberbis (Mediterranean Cardinalfish)
• Symphodus tinca (East Atlantic Peacock Wrasse)
• Serranus scriba (Painted Comber)
• Serranus cabrilla (Comber)
• Oblada melanurus (Saddled Seabream)
• Chromis chromis (Mediterranean Damselfish)
• Thalassoma pavo (Ornate Wrasse)
• Diplodus sargus (White Seabream)
• Sarpa salpa (Salema Porgy)
• Mullus surmuletus (Striped Red Mullet)

Sponges

• Tethya aurantium (Golf Ball Sponge)
• Chondrilla nucula (Potato Sponge)
• Sarcotragus spinosulus (Black Leather Sponge)
• Chondrosia reniformis (Kidney Sponge)

Anemones

• Aiptasia mutabilis (Trumpet Anemone)

Molluscs

• Stramonita sp.
• Tarantinaea lignarius

Echinoderms

• Holothuria sanctori (Variable Sea Cucumber)
• Arbacia lixula (Black Sea Urchin)

Crustaceans

• Percnon gibbesi (Nimble Spray Crab)
  
  

Algae and marine plants

• Codium fragile (Dead Man’s Fingers)
• Dictyota dichotoma (Forked Ribbons)
• Padina pavonica (Peacock’s Tail)

Coastal birds

• Gulosus aristotelis (European Shag)

​How Fast Can an Alien Species Establish in the Mediterranean Through the Suez Canal?
​
The Suez Canal is much more than a shipping route. Since opening in 1869, it has also connected two previously separated marine ecosystems: the Red Sea and the Mediterranean.

This has allowed hundreds of non-native organisms, often called alien species or Lessepsian migrants, to enter Mediterranean waters. But how quickly can one of these species establish and spread?

The short answer is: sometimes within a decade, although spreading across much of the Mediterranean usually takes several decades.

Arrival is not the same as establishment

A species must pass through several stages before it becomes established:

1. Arrival: individuals, eggs or larvae enter through the canal.
2. Survival: They tolerate Mediterranean temperatures, salinity, food availability, and predators.
3. Reproduction: A sufficiently large population begins reproducing successfully.
4. Establishment: The population becomes self-sustaining.
5. Expansion: It spreads to new coastlines and islands.

Many species arrive but disappear without forming permanent populations. An alien species is only considered established when it can maintain a population without repeated arrivals from its native range.

Also, not every alien species becomes invasive. That term is generally reserved for established species that spread and cause ecological, economic, or human-health impacts.

What does the research show?

A 2024 study examined 772 historical records involving 130 non-indigenous fish species that entered the Mediterranean through the Suez Canal.

The researchers found that:

- More than half of the introduced fish became established in less than 10 years.
- The first major movement beyond the initial detection region took approximately four years.
- Subsequent geographical expansion occurred in steps averaging about 2.5 years.
- Reaching the central Mediterranean from Suez took approximately 21.5–22 years.
- The dominant direction of expansion was northward and then westward, passing through the Levant, southern Turkey, Cyprus, Greece, and eventually the central Mediterranean.

These figures describe broad historical patterns rather than a timetable that applies to every species.

Read the Scientific Reports study: https://www.nature.com/articles/s41598-024-57109-8.

How quickly can a species reach Greece?

Southern Greece, especially Rhodes, Crete, and the southeastern Aegean, is one of the first European regions encountered by species expanding northwest from the Levant.

For a relatively mobile fish, reaching southern Greek waters can take roughly 10–15 years after the beginning of a successful, detectable expansion. Slower species may require several decades.

Lionfish provide a striking example. Genetic and observational evidence indicates that Mediterranean lionfish spread from the Red Sea through the Suez Canal, established in the Levant, and then expanded through Cyprus, Turkey, and Rhodes using a stepping-stone pattern. Their appearance across these locations over relatively short intervals demonstrates how quickly a suitable, mobile species can expand.

Read the lionfish study: https://www.nature.com/articles/s41598-017-07326-1.

Other organisms move much more slowly. The tropical seagrass Halophila stipulacea, for example, was first reported in Rhodes approximately 25 years after the Suez Canal opened.

Review its Mediterranean invasion history: https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2020.00300/full.

Why are some species much faster?

Several factors determine the speed of establishment and expansion.

Mobility and reproduction

Fast-swimming fish and species with widely dispersed larvae can cover large distances. Species that reproduce early, produce many offspring, or spawn several times per year can establish more rapidly.

Sea temperature

Many Suez migrants originate in warm tropical or subtropical waters. The eastern Mediterranean is warmer than the western and northern parts of the basin, making it easier for heat-loving species to establish there.

Continued warming can make areas farther north and west more suitable, although temperature is not the only controlling factor.

Currents and connected habitats

Ocean currents can transport eggs, larvae, and drifting organisms. Continuous rocky coastlines, seagrass beds, or other suitable habitats act as stepping stones between populations.

Unsuitable habitat can slow or stop expansion even when two locations are geographically close.

Shipping

Ships can transport organisms in ballast water or on their hulls. This can produce long-distance jumps between ports, allowing a species to bypass the slower process of natural coastal expansion.

Detection delays

The first scientific record is rarely the exact moment a species arrived. Small populations can remain unnoticed for years, particularly in poorly monitored areas. Reported expansion times therefore combine biological spread with differences in monitoring and detection.

A realistic Mediterranean timeline

A simplified scenario might look like this:

- 0–4 years: Passage through Suez and initial establishment in the southeastern Mediterranean.
- 5–10 years: Expansion along the Levant, Egypt, Cyprus or southern Turkey.
- 10–15 years: Arrival in parts of southern Greece for faster-moving species.
- Approximately 20–25 years: Expansion into the central Mediterranean around Sicily, Malta, Tunisia or southern Italy.
- 30 years or more: Wider expansion toward the western Mediterranean.

Ship-assisted transport could shorten these times dramatically, while unsuitable habitat or reproductive failure could prevent establishment altogether.

 Why early monitoring matters

By the time an alien species is abundant and widely recognized, eradication may already be impossible. Monitoring near the Suez Canal, the Levant, Cyprus, southern Turkey, and southeastern Greece can provide an early warning before a species expands across the basin.

Fisher observations, citizen-science reports, environmental DNA sampling, and coordinated regional databases can all help detect new arrivals sooner.

The central lesson is that the process is not always slow. A successful alien fish may establish itself in less than a decade and reach Greece within roughly 10–15 years. Expansion into the central and western Mediterranean usually takes longer, but shipping, warming seas, and highly mobile life stages can accelerate the journey.

Use the interactive simulation below to compare slow, moderate, and fast-spreading species and explore how habitat suitability and ship-assisted movement change the timeline.

Protecting wildlife is not always about large conservation projects or expensive infrastructure. Sometimes, one of the most effective conservation tools is simply providing the right information in the right place.

This week, Merman Conservation installed two new awareness signs at Liri Beach in South-east Pelion, Greece. Their purpose is straightforward: to inform visitors that they are entering an area used by the Mediterranean monk seal (Monachus monachus), one of the world's rarest and most endangered marine mammals.

Why Information Matters

Most people who visit the beach want to enjoy nature without causing harm. However, many simply do not know that monk seals may be resting, swimming, or using nearby coastal caves.

By making this information visible, visitors can make informed choices that reduce unnecessary disturbance before it happens.

The signs encourage everyone to:

• Keep a respectful distance if a seal is observed.
• Stay quiet and avoid unnecessary noise.
• Never approach, feed, or attempt to touch a seal.
• Keep dogs under control and on a leash.
• Avoid entering nearby sea caves that may be important resting or breeding sites.
• Refrain from flying drones over the area.

These are simple actions, but together they can significantly reduce human disturbance.

Prevention Is Better Than Reaction

Wildlife conservation often focuses on responding after problems occur. Yet prevention is usually more effective, less costly, and better for both people and wildlife.

Educational signs are a practical example of preventive conservation. They create awareness before disturbance occurs, helping visitors become active participants in protecting sensitive habitats rather than unintentionally harming them.

When people understand why an area is important, they are far more likely to respect it.

Every Visitor Can Contribute

The future of the Mediterranean monk seal does not depend only on governments, scientists, or conservation organisations. It also depends on thousands of everyday decisions made by visitors, swimmers, boaters, photographers, and local communities.

Respecting wildlife requires no special equipment or expertise. It simply requires awareness and consideration.

Action Is Better Than Doing Nothing

Installing two signs will not solve every conservation challenge facing the Mediterranean monk seal. However, doing something meaningful is always better than doing nothing.

Conservation is built from many small actions that work together over time. Every informed visitor, every respectful encounter, and every disturbance that never happens contribute to creating a safer environment for this remarkable species.

At Merman Conservation, we believe that conservation begins with knowledge. By helping people understand the wildlife around them, we create opportunities for everyone to become part of the solution.
​
Sometimes, protecting one of the world's most endangered marine mammals starts with something as simple as reading a sign.

The first half of 2026 has already been an important period for the Greek Shark Logbook, with 40 shark observations recorded from 1 January to 30 June 2026.

These records do not show something “new” or unnatural happening in Greek waters. Sharks have always been part of the marine biodiversity of Greece and the wider Mediterranean. What is changing is that more people are now recording, photographing, and reporting them.
This is exactly why the Greek Shark Logbook exists: to collect verified observations, organise them in a structured database, and help the public, researchers, media and authorities better understand shark presence in Greece.

40 observations in six months.

From January to June 2026, the Greek Shark Logbook recorded observations from several parts of Greece, including the Ionian Sea, the Corinthian Gulf, the Saronic Gulf, the Aegean Sea, Crete, the Pagasetic Gulf, the Dodecanese, and northern Greece.

The records included nine shark species:

• Prionace glauca (Blue shark)
• Isurus oxyrinchus (Shortfin mako)
• Mustelus mustelus (Common smooth-hound)
• Hexanchus griseus (Bluntnose sixgill shark)
• Galeorhinus galeus (Tope shark)
• Carcharhinus plumbeus (Sandbar shark)
• Carcharodon carcharias (Great white shark)
• Scyliorhinus stellaris (Nursehound)
• Squalus blainville (Longnose spurdog)

The most frequently recorded species during this period was the blue shark, with 17 observations. This is not surprising, as blue sharks are naturally present in Greek waters and are often seen seasonally, especially when individuals approach coastal areas.

The second most recorded species was the shortfin mako, with 9 observations. Other records included smooth-hounds, sixgill sharks, tope sharks, and single observations of rarer or less frequently reported species.

More records do not automatically mean more sharks.

One of the most important messages from the 2026 data is this:
More observations do not necessarily mean that there are suddenly more sharks in Greece.

It often means that more people are noticing them, filming them, sharing them online, and reporting them to citizen science projects.

In the last few years, smartphones, social media, action cameras, fishing groups, and local news pages have made wildlife observations much more visible. A shark that may have gone unnoticed or undocumented 20 years ago can now be photographed, uploaded, and discussed within minutes.

This visibility is useful, but it can also create unnecessary fear when sightings are presented without context.

The Greek Shark Logbook helps separate observation from exaggeration. It allows records to be checked, organised and mapped rather than lost in social media posts, rumours or sensational headlines.

Fishermen are becoming more involved.

A very positive development is the increasing participation of fishermen.

Fishermen are often the first people to encounter sharks at sea. Their contribution is extremely valuable because they can provide practical information that is often missing from public posts, such as location, date, depth, fishing method, approximate size, condition of the animal, and whether it was released.

In the 2026 dataset so far, 20 out of 40 observations were linked to fishing activity. This shows how important the fishing community is becoming for shark monitoring in Greece.

This also follows a wider trend already seen in the Greek Shark Logbook: fishermen’s participation has been increasing over time, from 5.9% of records in 2024 to 15.8% in 2025 and around 20.7% so far in 2026.

This is a major step forward. When fishermen participate directly, the data become stronger, more accurate, and more useful for conservation.

Why does this matter?

Sharks are often discussed only through fear, attacks, or sensational media stories. In reality, they are part of the natural marine ecosystem, and many species are threatened or vulnerable because of fishing pressure, bycatch, habitat degradation, and slow reproduction.

For Greece, better shark data are important because they can help us understand:

• where different species are being observed,
• which species are appearing more often in public records,
• which areas produce repeated observations,
• how often sharks are caught, stranded or seen swimming near the coast,
• and how citizen science can support long-term biodiversity monitoring.

The Greek Shark Logbook is not only a sightings map. It is a growing evidence base.

From fear to knowledge.

Every shark observation should be treated carefully, but not with panic.
Seeing a shark in Greek waters does not mean that the sea is unsafe. It means that Greece still has important marine wildlife, including species that have existed in the Mediterranean long before modern tourism, social media, or news headlines.

The real challenge is not to create fear. The challenge is to collect better information.

For every observation, the most useful details are:

1. date,
2. location,
3. photo or video,
4. species if known,
5. estimated size,
6. condition of the animal,
7. and how it was observed.

These details help transform a simple sighting into useful biodiversity data.

A stronger network for Greek shark records.

The first half of 2026 shows that the Greek Shark Logbook is growing. More observations are being collected, more areas are being represented, and more fishermen are participating.
This is important for science, conservation, and public education.

Sharks in Greece should not be treated as monsters, rumours or clickbait. They should be recorded, studied and understood as part of the country’s marine biodiversity.

The message from the first half of 2026 is clear:
​
Sharks are present in Greek waters, people are reporting them more often, and with the help of fishermen, citizens, and local communities, Greece can build a much stronger picture of its shark biodiversity.

On June 27, 2026, our team conducted a marine survey bioblitz, exploring the coastal habitats of Platanias and Mikro in South-east Pelion, Greece. The survey recorded a wide range of marine life from shallow rocky shore, sandy seabed, and nearshore habitats, including fish, sponges, corals, anemones, molluscs, sea slugs, echinoderms, hydroids, marine worms, and algae.

A total of 25 marine taxa were recorded during the survey, including 23 identified to species level and 2 identified to genus level.

​Fish

• Sphyraena sp.
  Recorded at Platanias
• Diplodus annularis (Annular Seabream)
  Recorded at Platanias
• Bothus podas (Wide-eyed Flounder)
  Recorded at Mikro
• Dactylopterus volitans (Flying Gurnard)
  Recorded at Platanias and Mikro
• Chelon sp.
  Recorded at Mikro
• Belone belone
  Recorded at Mikro
• Lithognathus mormyrus (Striped Seabream)
  Recorded at Mikro
• Parablennius zvonimiri (Zvonimir’s Blenny)
  Recorded at Platanias
• Oblada melanurus (Saddled Seabream)
  ​Recorded at Platanias

Sponges

• Sarcotragus spinosulus (Black Leather Sponge)
  Recorded at Mikro
• Aplysina aerophoba (Gold Sponge)
  Recorded at Platanias

Cnidarians, corals, anemones, and hydroids

• Pennaria disticha (Christmas Tree Hydroid)
  Recorded at Mikro
• Parazoanthus axinellae (Yellow Cluster Anemone)
  Recorded at Mikro
• Cladocora caespitosa (Cushion Coral)
  Recorded at Mikro
• Anemonia viridis (Snakelocks Anemone)
  Recorded at Platanias

Molluscs and sea slugs

• Cratena peregrina (Wandering Cratena)
  Recorded at Mikro
• Calmella cavolini
  Recorded at Mikro
• Thuridilla hopei
  Recorded at Platanias
• Mytilus galloprovincialis (Mediterranean Mussel)
  Recorded at Platanias

Echinoderms

• Echinaster sepositus (Mediterranean Red Sea Star)
  Recorded at Platanias and Mikro
• Holothuria tubulosa
  Recorded at Platanias

Marine worms

• Protula tubularia (Red-spotted Horseshoe)
  Recorded at Platanias

Algae

• Codium fragile (Dead Man’s Fingers)
  Recorded at Mikro
• Asparagopsis taxiformis (Red Sea Plume)
  Recorded at Mikro
• Acetabularia acetabulum (Mermaid’s Wine Glass)
  Recorded at Platanias

Since the start of the Greek Shark Logbook, our project has continued to evolve. What began as a way to collect and organise shark observations is gradually becoming a stronger bridge between science, local knowledge, and the people who encounter sharks at sea.

Most of our shark observations still come from social media, but we are encouraged to see that reports from fishermen are increasing year by year:

In 2024, 5.9% of records came from fishermen.
In 2025, this increased to 15.8%.
In 2026, so far, fishermen reports have reached 20.7%.

This progress is very important to us.

Fishermen spend countless hours at sea and hold valuable knowledge about marine life, shark presence, behaviour, and seasonal patterns. By working together, we can improve the quality of our data and build a clearer picture of the open data of shark species in Greek waters.

For every observation, we do our best to contact each observer directly and collect as much detail as possible, including location, date, length, photos or videos, and any other relevant information. All records are stored carefully in our database.

We are grateful to everyone who has contributed so far, from members of the public to fishermen, divers, researchers, and coastal communities.

Our goal is simple: better data, better understanding, and better protection for sharks in Greece.

If you are a fisherman and have seen or accidentally caught a shark, 

There is a tool available right now that lets you check whether jellyfish might arrive at your chosen beach before you pack your bag and head to the coast.

It tracks real sightings from real people, connects them to live weather and ocean drift data, and generates a probability forecast for the next five days. It sends instant alerts to your phone. It can be embedded by any local council, newspaper, or tourism website that wants to use it.

And it is completely free.

It is called the Pelagia Dashboard, and it is part of the Pelagia Logbook - a citizen science project now in its second year of monitoring Pelagia noctiluca, the Mauve Stinger jellyfish, across the coastlines of Greece.

🔗 https://pelagia.mermanconservation.co.uk/

More Than a Map.

At first glance, the Pelagia Dashboard looks like a simple database with a table and a map. Look closer, and it becomes something far more significant.

Every jellyfish bloom observation submitted by a citizen is logged individually, timestamped, and displayed on the map. But the system does not stop at recording where jellyfish have been. It uses real-time weather data and satellite-derived ocean drift information to model where those jellyfish are likely to go, projecting potential movement up to five days ahead.

For anyone planning a swim, a beach holiday, a coastal activity, or a diving session, this is genuinely transformative information.

What the Dashboard Can Do?

The Pelagia Dashboard offers a level of public functionality that, to our knowledge, no other jellyfish monitoring platform in the world currently matches:

• Individual observation browsing - every sighting is accessible and explorable on its own
• 5-day drift forecasting - based on weather and ocean current data, showing where jellyfish may move next
• Live beach-level probability - a same-day estimate of the likelihood of jellyfish presence at a specific beach or area
• Proximity alerts - showing how close the nearest recorded observation is to a user's chosen location
• Telegram bot alerts - instant notifications sent to subscribers the moment a new observation enters the database

These tools are not locked behind a subscription. They are not restricted to researchers or institutions. They are open to everyone.

Built for Communities, Not Just Scientists.

One of the most deliberate design choices behind the Pelagia Dashboard is the direction of information flow.

Most citizen science platforms are built around extraction: they ask the public to contribute observations, and the data flows upward to scientists, databases, and reports. The public rarely sees anything useful in return.

The Pelagia Logbook was built differently. The premise is simple: if people are generous enough to contribute their time and observations, they deserve to receive something genuinely useful back. The Dashboard returns that value immediately, in the form of forecasts, probabilities, alerts, and maps that help ordinary people make better decisions.

This matters especially in a country like Greece, where coastal tourism is a cornerstone of the economy, and where a jellyfish bloom can affect thousands of swimmers, beach operators, and local businesses in the space of a single day.

A Free Resource for Media, Municipalities, and Tourism.

The Pelagia Dashboard goes further still for organisations and institutions.

Newspapers, regional media outlets, municipal websites, tourism platforms, and local blogs can embed the dashboard, or filtered views of it, showing only the data relevant to a specific prefecture, coastline, or town, directly into their own platforms. For free.

This means a local authority in the Cyclades can display real-time jellyfish data for its own beaches. A travel website covering the Peloponnese can embed a live map filtered to that region. A regional newspaper can give its readers a tool they will actually return to, day after day, throughout the summer.

Why This Matters?

Pelagia noctiluca blooms are not a novelty. They affect swimmers, water sports operators, fishing communities, and coastal ecosystems. Their frequency and intensity are linked to broader patterns of sea temperature, seasonal variation, and environmental change. Understanding them is not merely a scientific interest; it has direct, practical consequences for millions of people every year.

The Pelagia Logbook is building a growing, georeferenced dataset of bloom events across Greece, one that improves in quality and coverage with every new observation. But crucially, it is not waiting until the dataset is complete before offering value. The Dashboard is live, functional, and useful today.

What Citizen Science Should Be!

The Pelagia Dashboard represents a model for how citizen science projects should operate: as a genuine exchange between the public and the scientific community, where contribution is met with usefulness, and where data serves people as much as it serves research.

If you are spending time on Greek beaches this summer, or if you know someone who is, the Pelagia Dashboard is worth bookmarking.

And if you run a local media outlet, a municipal website, or a tourism platform, it is worth getting in touch.

🔗 Explore the Pelagia Dashboard: https://pelagia.mermanconservation.co.uk/

The Pelagia Logbook is a project by Merman Conservation. The Dashboard is free and open to the public.

On May 27, 2026, our team conducted a marine survey bioblitz, exploring the coastal habitats of Neraki and Agrielia beaches, a small gulf in South-east Pelion, Greece. The survey recorded a wide range of marine life from shallow rocky shore and nearshore habitats, including fish, sponges, corals, anemones, molluscs, crustaceans, echinoderms, and algae.

Fish

• Apogon imberbis (Mediterranean Cardinalfish)
  Recorded at Neraki
• Oblada melanura (Saddled Seabream)
  Recorded at both beaches
• Parablennius gattorugine (Tompot Blenny)
  Recorded at Neraki
• Parablennius zvonimiri (Zvonimir’s Blenny)
  Recorded at Neraki
• Symphodus mediterraneus (Axillary Wrasse)
  Recorded at Neraki
• Sparisoma cretense (European Parrotfish)
  Recorded at Agrielia
• Thalassoma pavo (Ornate Wrasse)
  Recorded at Agrielia
• Sarpa salpa (Salema Porgy)
  Recorded at Agrielia
• Family Mugilidae (Mullets)
  Recorded at Agrielia

Sponges

• Chondrosia reniformis (Kidney Sponge)
  Recorded at Neraki
• Sarcotragus spinosulus (Black Leather Sponge)
  Recorded at Neraki
• Clathrina clathrus
  Recorded at Neraki
• Genus Cliona
  Recorded at Agrielia

Cnidarians, corals and hydroids

• Cladocora caespitosa (Cushion Coral)
  Recorded at Neraki
• Parazoanthus axinellae (Yellow Cluster Anemone)
  Recorded at Neraki
• Genus Aiptasia (Trumpet Anemones)
  Recorded at Neraki
• Aiptasia mutabilis (Trumpet Anemone)
  Recorded at Agrielia
• Genus Eudendrium
  Recorded at Agrielia

Molluscs and sea slugs

• Elysia timida
  Recorded at Neraki and Agrielia
• Calmella cavolini
  Recorded at Neraki
• Edmundsella pedata (Pink Coryphella)
  Recorded at Neraki
• Arca noae (Noah’s Ark Shell)
  Recorded at Neraki
• Pinctada radiata (Rayed Pearl Oyster)
  Recorded at Neraki
• Patella caerulea (Mediterranean Limpet)
  Recorded at Neraki
• Genus Patella (Patella Limpets)
  Recorded at Neraki

Crustaceans

• Pachygrapsus marmoratus (Marbled Crab)
  Recorded at Agrielia
• Perforatus perforatus (Perforated Barnacle)
  Recorded at Neraki
• Family Balanidae
  Recorded at Neraki

Echinoderms

• Holothuria sanctori (Variable Sea Cucumber)
  Recorded at Neraki
• Arbacia lixula (black sea urchin)
  Both beaches
  
  

Algae

• Flabellia petiolata (Fan Weed)
  Recorded at Neraki
• Acetabularia acetabulum (Mermaid’s Wine Glass)
  Recorded at Agrielia

When we talk about biodiversity, we often think about the number of species found in a place. Birds, insects, plants, sharks, rays, corals, seagrasses, mammals, fungi, and all the living systems that make an ecosystem function.

But biodiversity is not only about whether a species is present.

It is also about whether that species is still there in healthy numbers, whether habitats still function properly, and whether the natural balance of an ecosystem has been maintained or slowly pushed out of place.

This is where the Biodiversity Intactness Index (BII), becomes useful.

The Biodiversity Intactness Index is a scientific measure that estimates how much of an area’s original biodiversity remains compared with an undisturbed or minimally disturbed natural baseline.

In simple terms, BII asks:

How intact is nature here compared with how it would be without major human pressure?

A BII score is usually expressed as a percentage.

A score close to 100% suggests that an ecosystem is still close to its natural state. Species are not only present, but many are still found in the kinds of numbers expected in a healthy, functioning habitat.

A lower score suggests that human pressures such as land conversion, pollution, overexploitation, urbanisation, intensive agriculture, coastal development, or habitat fragmentation have reduced the abundance of originally present species.

This makes BII more powerful than a simple species list. A species list may tell us what has been recorded. BII helps us understand how much ecological integrity remains.

For conservation, this distinction matters.

An area may still contain wildlife, but if most species are present only in very low numbers, or if sensitive species have disappeared and only disturbance-tolerant species remain, the ecosystem may no longer be functioning as it once did. BII helps translate this ecological change into a clear, comparable indicator.

At Merman Conservation Expeditions Ltd, we see BII as a valuable tool for connecting science, fieldwork, public engagement, and practical decision-making.

Our work already combines marine and terrestrial conservation, ecological research, environmental consulting, citizen science, education, and digital systems. Integrating BII into this work gives us a stronger framework for measuring not only where biodiversity exists, but how intact and resilient those ecosystems are.

For our conservation projects, BII can help us identify priority areas more clearly. By combining BII data with field surveys, species records, camera trap data, shark and ray sightings, habitat assessments, community observations, and local ecological knowledge, we can build a more complete picture of biodiversity conditions.

This can help us answer important questions:

• Which habitats are still relatively intact and need urgent protection before they are degraded?
• Which areas have already lost biodiversity but could recover through restoration?
• Where are human pressures increasing fastest?
• Which conservation actions are likely to deliver the greatest ecological benefit?
• How can we measure progress over time, instead of only reporting activity?

For marine and coastal work, BII can also support broader ecosystem thinking. Many of the species we care about, including sharks, rays, fish, seabirds, marine mammals, seagrasses, and coastal invertebrates, depend on connected and functioning habitats. A degraded coastline, damaged nursery area, polluted bay, or fragmented marine landscape does not affect one species alone. It affects the whole web of life.

By using BII alongside species-specific monitoring, we can better understand the condition of the wider ecosystem that supports those species.

This is especially important for projects such as shark and ray monitoring. Recording sightings is essential, but the next step is understanding the habitat and ecological context behind those records. Are sightings increasing because populations are recovering, because reporting is improving, or because animals are being displaced from other areas? Are key habitats still intact? Are coastal pressures reducing the long-term ability of ecosystems to support these species?

BII does not answer every question by itself, but it gives us a strong starting point for deeper investigation.

For our consulting work, BII can help organisations make better nature-related decisions.

Businesses, landowners, developers, tourism operators, supply chains, funders, and public bodies are increasingly expected to understand their impacts and dependencies on nature. Biodiversity is no longer just an environmental issue. It is becoming a planning, risk, compliance, investment, and reputation issue.

Through consulting, Merman Conservation can use BII as part of a wider biodiversity assessment process to help clients:

1. Map biodiversity risk across sites or project areas.
2. Understand whether activities are taking place in highly intact, degraded, or recovering ecosystems.
3. Screen projects before development decisions are made.
4. Identify where restoration, avoidance, mitigation, or biodiversity net gain actions are most needed.
5. Support reporting aligned with emerging nature-related frameworks.
6. Build practical biodiversity strategies that are grounded in evidence rather than vague commitments.

BII can also help make biodiversity communication clearer. Many people understand carbon because it can be measured, tracked, and reported. Biodiversity is more complex, but tools like BII help make the condition of nature easier to explain without oversimplifying the science.

For Merman Conservation, this is important because we believe conservation should be transparent, accessible, and useful. Good data should not stay locked away in technical reports. It should inform decisions, support communities, guide restoration, improve policy, and help people understand what is happening to the natural world around them.

By integrating BII into our work, we can achieve several important outcomes.

• We can improve conservation planning by identifying where action is most urgent.
• We can strengthen project design by linking activities to measurable biodiversity outcomes.
• We can support restoration by tracking whether the biodiversity condition is improving over time.
• We can help clients understand their nature-related risks and opportunities.
• We can make biodiversity reporting more credible, practical, and science-based.
• We can connect citizen science and professional ecological assessment into a stronger evidence base.
• Most importantly, we can move from simply describing biodiversity loss to actively measuring, managing, and reversing it.

BII is not a replacement for local ecological surveys, species monitoring, community knowledge, or expert fieldwork. Instead, it is a complementary tool. Its real value comes when it is combined with on-the-ground evidence, local context, and practical conservation action.
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That is the approach we want to take at Merman Conservation.

We want to use BII not just as a number, but as a decision-making tool.

A way to see where nature is still strong.

A way to identify where it is under pressure.

A way to measure whether our actions are making a real difference.

And a way to help communities, organisations, and partners work toward a future where biodiversity is not only protected on paper, but restored in the places that need it most.

Because conservation is not only about counting what remains.

​It is about understanding what has been lost, protecting what is still intact, and rebuilding the living systems that support both wildlife and people.