Sharks and rays have survived for hundreds of millions of years, but many populations have been heavily depleted by fishing, habitat loss, and other pressures. Resharking is about reversing that trajectory by protecting sharks and rays, restoring populations, and creating the conditions for recovery.

But a shark population does not recover simply because sharks are seen again.

You need to know whether populations are increasing, whether their distribution is changing, whether individuals are reaching larger sizes and reproducing, whether mortality is declining, and whether the ecological conditions that support recovery are improving.

You also need to understand what recovery means for people.

As shark populations recover, interactions with fisheries, tourism, coastal communities, and other ocean users can change. A successful conservation intervention can create new management questions that did not exist when populations were depleted.

Resharking therefore requires an evidence system that can track both ecological recovery and the changing relationship between sharks, their habitats, and people.

What does shark recovery actually look like?

There is no single measure of recovery.

Depending on the species, location, and objective, you may need to track abundance, distribution, size structure, age structure, sex ratios, reproduction, survival, movement, habitat use, fishing mortality, bycatch, effort, or changes in community composition.

You may also need to understand broader ecological responses. Are sharks returning to habitats where they were historically common? Are different species responding differently? Are protected areas being used? Are juveniles appearing in nursery habitats? Are large adults becoming more common?

And because sharks and rays are highly diverse, recovery will not necessarily happen at the same rate across species or places.

A monitoring program therefore needs to capture enough information to distinguish more observations from actual population recovery.

How do you know whether populations are recovering?

Seeing more sharks can be encouraging, but observations alone do not establish a population trend.

Detection changes with sampling effort, location, season, visibility, gear, observer, and many other factors. A dive operator that doubles the number of dives may record twice as many sharks without there being any change in shark abundance.

That is why good monitoring records the context around an observation.

Where was the shark observed? When? By whom? Using what method? Under what conditions? How much effort was involved? What species was it? What was its size, sex, behaviour, or identification confidence?

With that information, observations can be analyzed in relation to effort and other factors rather than simply counted.

eOceans is designed to capture that context as part of the observation itself, making repeated monitoring much more useful for detecting change.

What about species that are difficult to find?

Sharks are not distributed evenly through the ocean, and many species are difficult to detect.

Some spend much of their time in deeper water. Others are highly mobile. Some occur in low densities or are naturally rare. Juveniles may occupy different habitats from adults. Some species are easier to detect using fishing surveys, others through visual surveys, acoustic methods, tagging, environmental DNA, or photographic identification.

That means a useful resharking program often needs multiple methods and data sources.

A diver observation can tell you something a trawl survey cannot. A fisheries dataset can reveal patterns that a tourism monitoring program will miss. A satellite tag can show movement across enormous distances. Environmental DNA may detect a species without an individual ever being seen.

The objective is not to make every observation comparable. It is to understand what each observation can tell you and connect the evidence appropriately.

Can citizen science and tourism observations contribute?

Absolutely — if the data are collected with enough context to be useful.

Divers, fishers, tourism operators, researchers, coastal communities, and other ocean users can collectively observe sharks across enormous areas and time periods that would be impossible for a single research team to cover.

Photographs can document species and individual identity. Dive surveys can provide repeated observations at particular sites. Fishers can provide information about catch, effort, size, location, and interactions. Communities can report sightings or strandings.

These observations can become particularly powerful when they are connected to structured monitoring rather than sitting in separate databases.

eOceans can support both structured surveys and opportunistic observations while retaining information about how each observation was produced.

That makes it possible to use the right evidence for the right question rather than treating every sighting as equivalent.

How do you connect shark recovery to fishing pressure?

A population can be increasing in one area while still experiencing substantial fishing pressure elsewhere.

Understanding recovery therefore often requires connecting biological observations with information about fishing activity, catch, effort, gear, mortality, habitat, and management measures.

For example, a change in shark observations might be interpreted differently depending on whether fishing effort has also changed, whether an area has become protected, whether habitat has changed, or whether sharks have shifted their distribution.

Connecting these datasets can help answer questions such as:

• Are shark observations changing where fishing pressure has declined?

• Are protected areas being used by recovering populations?

• Are juvenile sharks appearing in expected nursery habitats?

• Where are fishing interactions occurring?

• Are changes in catch driven by shark abundance, fishing effort, or both?

• Are management measures producing measurable changes?

The important point is that shark recovery cannot always be understood from shark data alone.

What happens when sharks and people interact differently?

Recovery can change human-wildlife interactions, and not all of them are straightforward.

As shark populations recover or expand into areas where they were previously uncommon, interactions with fisheries, swimmers, divers, tourism operators, and coastal communities may change. Some may be positive or benign. Others can create real costs, safety concerns, or conflict.

Shark depredation is a particularly complex example. A shark may take or damage a fish that a fisher has hooked while it is still on the line, resulting in lost catch, lost fishing time, damaged gear, and frustration for the fisher. At the same time, the interaction is evidence of a shark using the same environment and resources as the fishery.

Understanding the scale and distribution of depredation can therefore be important for both fisheries management and shark conservation.

Simply recording that a shark was present does not capture this interaction.

You may need to know where and when it occurred, what fishery and gear were involved, what species were being targeted, how much fishing effort was taking place, whether a shark was observed, what was lost or damaged, environmental conditions, and whether the interaction is becoming more or less frequent.

Those details can help distinguish isolated encounters from persistent patterns and identify where conflict is emerging.

They can also help evaluate mitigation. If changes in fishing practices, gear, timing, spatial management, or other interventions are introduced, the same monitoring system can track whether depredation changes afterward.

The goal is not simply to reduce interactions at any cost. It is to understand the interaction well enough to find approaches that support both viable fisheries and recovering shark populations.

The same evidence system can therefore support shark conservation, fisheries management, and the people whose livelihoods depend on the ocean.

How do you know whether protection is working?

Protection is an intervention. It is not the outcome.

Declaring an area protected does not automatically mean shark populations will recover.

You need to understand whether protection changes the pressures affecting sharks and whether those changes produce biological responses.

That may require connecting:

Management → human activity → habitat conditions → shark response → population outcome

For example, monitoring could combine shark observations with fishing activity, enforcement information, habitat condition, and effort over time.

This provides a much stronger basis for understanding whether a management measure is associated with the intended ecological response.

What if recovery looks different from what you expected?

That is often where the most useful science begins.

A species may recover in one location but not another. Adults may return before juveniles. A population may increase without expanding its range. Sharks may shift habitats in response to changing temperature or prey availability. One species may respond strongly to protection while another shows little change.

Those differences can reveal what is actually limiting recovery.

Continuous monitoring makes it possible to detect these patterns while they are developing rather than discovering them years later in a retrospective analysis.

What about the decades of shark data that already exist?

There is an enormous amount of shark and ray information already available.

It exists in research datasets, fisheries records, government monitoring, tagging programs, dive surveys, photographic identification projects, tourism programs, citizen science, historical records, environmental assessments, reports, spreadsheets, and databases around the world.

The problem is often not a lack of observations. It is that the observations were collected using different methods, stored in different places, described using different taxonomies, and analyzed separately.

That makes it difficult to see the larger picture.

eOceans allows existing datasets to be brought together with new observations while preserving the information needed to understand their provenance, methods, effort, location, and timing.

That means a new monitoring program does not have to begin with an empty database. It can build on what is already known.

From shark observations to recovery evidence

The field observation is only the beginning.

Someone still has to design the database, establish protocols, onboard contributors, validate species identifications, standardize information, manage spatial data, account for effort, run analyses, produce maps and graphs, update reports, and communicate results.

For many shark and ray programs, that technical work has to be rebuilt repeatedly across projects and organizations.

eOceans automates much of that repeatable infrastructure.

You define your questions, methods, data requirements, and analyses. Your team can collect observations in the field, upload existing datasets, incorporate information from other sources, and continue adding data as monitoring progresses.

eOceans validates and organizes the information, connects observations spatially and temporally, performs analyses, produces maps and visualizations, and keeps reports and other outputs current as new evidence arrives.

The scientific judgment remains with the people doing the work.

The system handles more of the machinery around it.

Resharking needs evidence that can keep up with recovery

Shark recovery is not a single measurement at the end of a conservation program. It is a process that unfolds across species, habitats, jurisdictions, fisheries, communities, and years.

The evidence needs to work the same way.

You need to be able to bring together observations from researchers, fishers, divers, tourism operators, governments, communities, sensors, tagging programs, remote observations, and existing datasets. You need to understand how those observations were collected, analyze them in the appropriate context, and continuously update the evidence as new information arrives.

That is what eOceans is built to do.

Connect the observations. Understand the change. Measure recovery. Adapt management.

eOceans gives resharking programs the system to collect, connect, validate, analyze, and share the evidence needed to understand shark and ray recovery — and the changing relationships between sharks, ecosystems, fisheries, and people.

—> Get powered by eOceans®.