Certification of long-lived freshwater fish
DREVO Fish Passport— a system of individual digital recording of large, long-lived, rare and reproductively valuable freshwater fish.
Basic age for inclusion in the program:
16 years is the beginning of age certification of long-lived fish species.
However, age should not be determined solely by size. A confirmed observation history, tags, scale and fin ray examinations, and other species-specific methods are used to assign a passport.
Main types for certification
| Priority | Fish | Potential life expectancy | Passporting | Reason for priority |
|---|---|---|---|---|
| ⭐⭐⭐⭐⭐ | Beluga (Spindle spindle) | Several decades, potentially over 100 years | From 16 years of age or earlier for rare individuals | An exceptionally long-lived and rare species |
| ⭐⭐⭐⭐⭐ | Sturgeons (Acipenser spp.) | 30–150 years depending on the species | Since 16 years old | Late maturity, high reproductive value |
| ⭐⭐⭐⭐⭐ | Sterlet (Acipenser ruthenus) | More than 20 years | Since 16 years old | A valuable local sturgeon species |
| ⭐⭐⭐⭐⭐ | European catfish (Catfish) | Up to 80 years according to registered data | Since 16 years old | A large apex predator, easily distinguishable by its size and features |
| ⭐⭐⭐⭐⭐ | Carp / common carp (Cyprinus carpio) | Often 20–40 years, some individuals longer | Since 16 years old | Large breeders and important long-lived individuals |
| ⭐⭐⭐⭐⭐ | European eel (Anguilla anguilla) | Typically years and decades in fresh water, sometimes up to 50 years | Since 16 years old | Critically endangered migratory species |
| ⭐⭐⭐⭐ | Pike (Pike perch) | Large individuals can live for more than 20 years. | From 16 years of age after confirmation | An apex predator that regulates the fish community |
| ⭐⭐⭐⭐ | Nalim (Lol lol) | May exceed 20 years | Since 16 years old | Cold-water bottom predator |
| ⭐⭐⭐⭐ | Bream (Abramis brama) | Can live for more than 20 years | Since 16 years old | Large old individuals are important for population structure |
| ⭐⭐⭐⭐ | Tench (Tench tench) | About 15–20 years and more in some individuals | After age verification | A valuable inhabitant of overgrown floodplain reservoirs |
| ⭐⭐⭐ | Zander (Sander lucioperca) | Sometimes around 20 years | Conditionally sentenced from the age of 16 | A large predator, but those aged 16+ are less common. |
| ⭐⭐⭐ | Jereh (Aspfish) | Can reach a considerable age | After confirmation | A large river predator |
| ⭐⭐⭐ | Chub (Squid head) | Some individuals may exceed 16 years of age. | After confirmation | Indicator of connectivity and condition of river habitats |
| ⭐⭐⭐ | Tongue (Leuciscus ides) | May exceed 16–20 years | After confirmation | Large adult fish of river and floodplain systems |
| ⭐⭐⭐ | White amur (Ctenopharyngodon idella) | More than 20 years | Only in commercial and permitted populations | A long-lived species, but often introduced |
| ⭐⭐ | Silver carp (Hypophthalmichthys spp.) | More than 16–20 years | Only in controlled commercial water bodies | Introduced species should not receive conservation priority. |
1. European catfish
Why is catfish one of the main species?
European catfishis one of the longest-lived and largest freshwater fish in Europe. The maximum recorded age reaches approximately80 years old.
Big old catfish:
regulates the number of fish;
occupies the top level of the food web;
uses deep holes and complex bottom shelters;
can remain in one river or reservoir complex for decades;
is an indicator of the presence of stable wintering areas.
Suggested catfish classes
| Class | Estimated age | Status |
|---|---|---|
| S1 | Up to 8 years | A young individual |
| S2 | 8–16 years old | Adult |
| S3 | 16–25 years old | Passport age of the individual |
| S4 | 25–40 years old | A particularly valuable specimen |
| S5 | More than 40 years | The Living Heritage of the River |
The exact age cannot be determined solely by length: the growth rate of catfish is highly dependent on temperature, food supply, and the reservoir.
2. Carp and Carp
Terms
Carp- wild formCyprinus carpio.
Carp— cultural and economic forms of the same species.
For the environmental protection program, priority should be given to:
wild carp;
local stable populations;
large old manufacturers;
genetically valuable lines.
Why is old carp important?
Large adult carps and grass carps:
produce a large amount of caviar;
transfer genetic material between generations;
survived diseases, floods, droughts and temperature fluctuations;
are of interest for studying the history of the reservoir;
may be re-detected by scale patterns, scars, and body shape.
Suggested carp classes
| Class | Estimated age | Status |
|---|---|---|
| C1 | Up to 8 years | A young or maturing individual |
| C2 | 8–16 years old | Mature producer |
| C3 | 16–25 years old | Passport age of the individual |
| C4 | 25–40 years old | Particularly valuable producer |
| C5 | More than 40 years | An exceptionally rare specimen of age |
Farmed carp from a commercial pond should not automatically receive protected status. A passport may be:
economic;
selection;
genetic;
nature conservation.
These categories need to be separated.
3. Sturgeon
Sturgeons receive top priority regardless of whether they are 16 years old or older if the species is rare or protected.
Some sturgeons live extremely long lives: lake sturgeon can reach approximately 150 years of age, while females do not mature for the first time until they are around 20 years old.
Atlantic sturgeon have a lifespan of up to 60 years in northern populations; females can reach sexual maturity at 30 years.
Status
young sturgeon;
mature individual;
confirmed manufacturer;
age-related individual;
particularly valuable genetic producer;
living heritage of the catchment.
4. European eel
The European eel spends a long growth period in rivers and lakes. Depending on the region, this period can range from a few years to 20 years, and some individuals can remain in freshwater for up to 50 years.
The eel passport is especially important because:
complex migration;
critical environmental situation;
barriers on rivers;
difficulties of re-detection;
great value mature silver eels.
For an eel, a passport should be created not only based on age, but also upon transition to the stage of a migratory silver eel.
5. Fish with conditional age certification
These species can live for more than 16 years, but not every population reaches this age:
pike;
zander;
slush;
bream;
tench;
ide;
chub;
large perch;
cumin;
individual whitefish;
some trout in cold lakes.
A passport is issued after confirmation of age or a long-term observation history.
6. Which fish do not require an individual passport based on age?
For most short-lived species, a population passport is more effective.
These include:
bleak;
gudgeon;
ruff;
verkhovka;
most small bulls;
bitterling;
sticklebacks;
young crucian carp;
small roach fish.
For them, it is created:
DREVO Fish Population Passport, containing data on population size, reproduction, genetic status and habitat.
7. What is recorded in the individual fish passport?
| Section | Data |
|---|---|
| Identification | DREVO Fish ID |
| View | Common and scientific name |
| Status | Local, rare, protected, commercial or introduced |
| Floor | If defined |
| Age | Confirmed or estimated |
| Length | General and standard |
| Weight | Measured or estimated |
| Distinguishing features | Scars, scale patterns, damage, coloring |
| Genetics | Sample and population membership |
| Place | Reservoir, area, depth |
| History | All repeat detections |
| Reproduction | Participation in spawning |
| Health | Damage, parasites, body condition |
| Wednesday | Temperature, oxygen, depth, current |
| Conservation status | Level of protection |
8. How River Rover Scout creates a passport
Stage 1 - Detection
Used:
sonar;
side view;
multibeam echo sounder;
underwater cameras;
hydroacoustic tracking.
Step 2 - Measurement
The following are determined:
length;
body height;
approximate weight;
speed of movement;
depth;
character of behavior.
Step 3 – Visual Identification
DREVO AI compares:
head shape;
shape of the fins;
scale pattern;
scars;
damage;
spots;
body proportions.
Step 4 - Confirmation
If necessary, apply:
PIT tag;
external safe transmitter;
genetic sample;
fin ray study;
data from the previous issue;
repeated observations.
Stage 5 – Digital Twin
A story is being created for the fish:
movements;
wintering;
feeding;
spawning;
flood response;
reactions to cleaning and restoration of the riverbed.
9. DREVO Fish Passport Top Ten
| Place | View | Cause |
|---|---|---|
| 1 | Beluga | Maximum Longevity and Critical Value |
| 2 | Other sturgeons | Late maturation and high vulnerability |
| 3 | European catfish | Up to 80 years old, a large apex predator |
| 4 | Carp | Long-lived mass producer |
| 5 | European eel | Long life and unique migration |
| 6 | Pike | Top predator and population regulator |
| 7 | Nalim | A long-lived cold-water predator |
| 8 | Bream | Large old manufacturers |
| 9 | Tench | A long-liver of floodplains and overgrown reservoirs |
| 10 | Zander | A large predator of reservoirs and rivers |
The main principle
A passport is awarded not just to a large fish, but to a confirmed long-lived individual of ecological, reproductive, genetic, or scientific value.
For the systemDREVO Living MountainsThe main age-specific passport fish of Europe should be:
sturgeon;
European catfish;
carp and carp;
European eel;
pike;
slush;
bream;
tench;
zander.
At the same timecatfish and carp should be considered as independent key areas for certification, as they can live for decades, reach large sizes, and preserve the history of a particular body of water for a significant portion of a human life.