What does a Fish Need to Survive?

Today we embark on the journey of understanding what are the basic necessities of fish needed to survive. From ponds, to lakes, to rivers, and even oceans we will cover what elements allow a fish to thrive. These elements impact the behavior of a fish. Understanding why fish do what they do can help you predict their behavior as an angler. Recognizing patterns based on habitat, food, or weather will set you up for success in terms of getting fish to bite. Let’s explore how understanding the needs of a fish can help you get more in the boat!

Clean Water

Just as clean air is vital for us, clean water is essential for fish. It provides oxygen for respiration and removes waste products. Maintaining proper water quality parameters such as pH, temperature, and ammonia levels is crucial for fish health. For example, spending time in Fort Myers, FL the past couple of years has opened my eyes on what poor water quality can do to a fish. Witnessing the impacts of the Red Tide Bloom was quite alarming. Dead fish floating everywhere, discolored red water, and even tourists getting sick were some of the symptoms caused by this nasty algae bloom. The Fishing really took a hit as well, the organism caused by red tide produces a toxic chemical that negatively impacts the central nervous system of fish. Red tide aside, what are some things you can look for as a fisherman to determine if water is clean enough for good fishing?

Goliath Grouper Red Tide
A once healthy, Goliath Grouper, washes up on the shores of Sanibel due to poor water quality caused by Red Tide.
  1. Water clarity – You can gauge water clarity by observing how easily you can see objects beneath the surface. Murky or turbid water may indicate sedimentation or pollution.
  2. Water flow – Adequate water flow helps maintain oxygen levels and flushes out pollutants. Look for signs of healthy water flow, such as riffles, riffle pools, and runs, which provide oxygen-rich environments for fish.
  3. Water temperature – Clean water tends to maintain a relatively stable temperature compared to polluted water. Fish thrive in water within their preferred temperature range, so monitoring water temperature can help you assess water quality.
  4. Presence of wildlife – Healthy water bodies support a diverse array of wildlife, including birds, insects, and other aquatic animals. Observing wildlife activity can provide clues about the overall health of the ecosystem.

Abundance of Habitat

As a fisherman, recognizing signs of good habitat can greatly enhance your chances of finding fish in an area. Here are some key indicators to look for:

Pike Habitat
  1. Structural Features: Fish are often attracted to structural features such as submerged logs, fallen trees, rock formations, and underwater vegetation. These structures provide shelter, protection from predators, and ambush points for feeding.
  2. Depth Changes: Fish are typically found in areas where there are changes in water depth, such as drop-offs, ledges, and underwater shelves. These features provide fish with access to different temperature zones, food sources, and refuge from strong currents.
  3. Current Breaks: Fish tend to congregate in areas where the current is slower, such as behind boulders, along the edges of weed beds, or in eddies formed by obstructions. These areas provide fish with an opportunity to conserve energy while waiting for food to drift by.
  4. Cover and Concealment: Fish prefer areas with ample cover and concealment to hide from predators and ambush prey. Look for places with overhanging vegetation, submerged brush piles, and undercut banks where fish can find shelter and security.

Nutrition and Food Availability

A balanced diet is essential for fish to maintain their health and vitality. Depending on the species, fish may require specific types of food such as algae, insects, or other fish. Providing a varied diet that meets their nutritional needs is crucial.

Feeding Bird
  1. Presence of Baitfish: Baitfish, such as minnows, shad, and herring, are often abundant in areas with ample food sources. Look for signs of baitfish activity such as surface disturbances, schooling behavior, or birds diving to feed on baitfish.
  2. Aquatic Insects: Aquatic insects are a primary food source for many freshwater fish species. Look for signs of insect activity such as hatches, swarms, or surface dimpling caused by rising fish feeding on emerging insects.
  3. Weed Beds and Vegetation: Submerged weed beds and aquatic vegetation provide habitat and food sources for a variety of organisms, including insects, crustaceans, and small fish. Fish are often attracted to these areas to feed on the abundance of food available.
  4. Feeding Birds: Birds such as herons, kingfishers, and cormorants are excellent indicators of feeding activity in the area. Watch for birds diving, swooping, or hovering over the water surface, as they may be feeding on small fish or other prey.

Protection from Stressors

Fish are sensitive creatures, and exposure to stressors such as pollution, overcrowding, and sudden environmental changes can compromise their health and well-being. Minimizing stressors and providing a stable and suitable environment are key to ensuring fish survival.

Bass habitat

Fishermen can look for various signs of protection from stressors in an area to determine if fish are present and thriving:

  1. Sheltered Areas: Fish seek refuge in sheltered areas such as coves, undercut banks, submerged logs, and overhanging vegetation. These areas provide protection from predators, strong currents, and adverse weather conditions.
  2. Deep Water Pools: Deep water pools offer fish a sanctuary from fluctuating water temperatures, low oxygen levels, and predators. Look for areas with deep holes, submerged boulders, or natural depressions where fish can retreat during times of stress.
  3. Slow-Moving Currents: Fish prefer areas with gentle or slow-moving currents, as fast-flowing water can be stressful and energy-intensive to navigate. Look for backwaters, eddies, and slack-water areas where fish can conserve energy and avoid being swept away by strong currents.
  4. Minimal Human Disturbance: Fish are sensitive to disturbances such as noise, boat traffic, and shoreline development. Look for remote or secluded areas away from heavy human activity, where fish are less likely to be stressed by human disturbances.

Ability to Reproduce

Several factors that we mentioned above impact the ability of a fish to reproduce and continue the cycle. Clean water with optimal oxygen levels is essential, as poor water quality can harm reproductive systems and egg viability. Suitable spawning habitats are necessary for depositing eggs and fry development, and changes to habitat structure can hinder reproduction. Adequate food resources support energy reserves for reproduction. Water flow and currents transport eggs and larvae to suitable habitats, but alterations can disrupt spawning behaviors.

Tools that can Help

Based on what we know about what fish need to survive and thrive there are a couple of items that can aid in increasing your catch rate.

Fish Finders

Humminbird Fish Finder

You can use fish finders or depth sounders to locate underwater structures, depth changes, and concentrations of baitfish. This helps identify potential fishing spots where fish may be congregating to seek shelter or feed. I personally, like to do side imaging to understand what kind of debris I might be working with in the water column. Pay attention to rocks, logs, and other structures such as bridges or pylons to seek out fish.

Water Quality Test Kits

Pond Test Kit

This is an extreme measure you can take, but worth it if you are a dedicated angler. Portable water quality test kits allow you to assess water parameters such as pH, temperature, oxygen levels, and nutrient levels in real-time. This information can help you determine the likelihood of an area holding fish if you are unsure of the conditions.

Underwater Cameras

Go Pro Hero 10

Underwater cameras can provide visual confirmation of fish presence, habitat characteristics, and feeding behaviors. A tactic I like to use is to tie a rope on to my go pro and drop it off the side of the boat under bridges especially when I am fishing in saltwater. For one, you get a real idea and live footage of all the action that is going on down there which can be really cool to see. Schools of bait fish and other marine life are real good signs as these all play a vital role in a healthy ecosystem. You might even be able to catch a glimpse of the fish you intend to target.


Use the knowledge above regarding what a fish needs to survive, to plan your next fishing trip. Understanding elements like clean water, habitat, food availability and spawning can all aid in your ability to catch more fish. Additionally, utilize some of the tools mentioned above to increase your chances. To catch more fish, you have to think like a fish. The more knowledge you have about the behavior of a species the better you will do. Do research beforehand on the areas you will target whether it is a pond, lake, river, or ocean. Better preparation often leads to better fishing!

    Leave a Comment

    Your email address will not be published. Required fields are marked *

    Scroll to Top