Livewells – Bait Tanks – Water Quality

Livewells and bait tanks  http://en.wikipedia.org/wiki/Livewell  are used to keep live bait and tournament fish alive and healthy during transport. Livewells and bait tanks are boxes that hold water, made of materials that are non-toxic to live bait and fish.

Minimal safe water quality is necessary to keep live bait and fish alive and healthy during transport. Dissolved Oxygen Saturation is the most important water quality parameter.

ABOUT LIVEWELLS AND BAIT TANKS

Livewell  internal shape is important for active transports, less important for stationary use. Most stationary fish aquariums have square or rectangular 90 degree corners. When the water and bait are sloshing during active transport conditions on water or on land, round and oval tanks cause less physical trauma.

LIVEWELLS AND WATER QUALITY

One gallon of water weighs approximately 8 pounds.

Livewell and bait tank water quality is more important than the shape of the livewell and bait tank “box.”

FACT: Low dissolved oxygen saturations and suffocation is the primary killer of live bait and fish being transported every summer. Mechanical aerators and water pumps do not, cannot and will not ensure minimal safe oxygenation in hot summer livewell water, they pump air and water… not oxygen.

Minimal safe dissolved oxygen is the most important livewell water quality parameter.  DO Saturation limits stocking density in all livewells.  Most summer livewell mortality is caused by the fisherman’s failure to safely  oxygenate his livewell – bait tank water.

AERATED LIVEWELL WATER IS BETTER THAN NO AERATION

But, air is not oxygen, air is 80% Nitrogen, an inert filler gas.

Standard stocking density for aerated livewells is one pound or less live bait or fish per one gal of water.   The limiting factor for stocking density in aerated livewells is Air.

Aerated livewells require more water volume per pound of live bait and fish than oxygenated livewells.

FACT: Aeration often fails to ensure minimal oxygen saturations in the summer (livewell water temperature 75 F – 95 F), the most common cause of high livewell mortality.

FACT: Oxygenated livewell water ensures the best livewell water quality even in the worst hostile summer conditions.

 FACT: Oxygen Saturations should be maintained at 100% DO or greater using supplemental pure 100% oxygen continuously during live transport,which is the fish hatchery standard. Oxygenated livewell water requires less water per pound of live bait or fish.  Standard stocking density is 2-3 pounds of live bait or fish per gallon of oxygenated water.

FACT: OXYGEN ENRICHED LIVEWELL GAS SPACE (>24% Oxygen) “oxygen rich”     CAUTION: FIRE SAFETY

The livewell gas space is above the water surface and the lid will become enriched with oxygen when high concentrations of supplemental oxygen is used. When the livewell lid is closed this gas space inside the livewell will become enriched with oxygen (> 24% oxygen) or “oxygen rich.” Any type of livewell oxygen system that produces or delivers 90% – 100% pure oxygen into livewell water will have an oxygen enriched gas space inside a closed livewell.

Oxygen is heavier than air, the highest concentration of gaseous oxygen will be at the water surface inside the livewell. If an oxygen system leaks pure oxygen into the boat bilge the oxygen also settles at the bottom of the bilge where fuel and oil accumulate. FIRE HAZARD.

INSULATED LIVEWELLS

Insulation helps maintain a constant temperature in the livewell water and gas space. Steady water temperature causes less bait and fish stress.

LIVEWELL DRAIN AT THE BOTTOM

A bottom drain aids in evacuating solid organic particulates that settle to the bottom of the livewell, feces, vomit, chunks of decomposing organic matter.

Maintaining minimal safe water quality is NECESSARY FOR SUCCESSFUL LIVE BAIT AND TOURNAMENT FISH TRANSPORT

Livewell and bait tank water quality is more important than the shape, size and color of the box.  The number and size of water pumps, volume of water pumped, volume of air pumped, type and number of air diffusers, all the alarms, switches, bells and buzzers combined are less important than maintaining minimal safe water quality..

* Minimal safe livewell and bait tank transport water must be

1. Oxygenated:   maintaining minimal safe dissolved oxygen saturation levels is most important.   Low oxygen (hypoxia) kills  and causes brain damage in seconds and minutes in livewells.

2. Ventilated:  water must be flushed and cleaned of toxins (second most important).   Metabolic toxins take hours and days to reach toxic levels that kill in livewells.

FACT: Livewell oxygen injection systems (adjustable dose) provide the very best and most efficient means of ensuring minimal safe livewell oxygenation.

The purpose of supplemental oxygen is to ensure minimal safe oxygenation for the total biomass of live bait and fish being transported for the duration of the transport in any summer condition. Oxygen injection systems are true “life support” systems. Oxygen injection systems are not aeration systems.

 

VENTILATING LIVEWELL WATER – REMOVING DISOLVED GASES AND METABOLIC TOXINS

FACT: Ventilating livewell water (intermittent partial and total water exchanges) reduces metabolic toxins, dissolved CO2, ammonia, nitrates, nitrites,  acid pH, vomit, scales and the big chunks.

Intermittent livewell partial and total water exchanges are the most effective, least expensive, easiest way to remove toxins and ventilate the livewell.

Larger stocking densities (more bait and fish) produce more waste toxins and consume more dissolved oxygen.

Bacteria consume tremendous amounts of dissolved oxygen in livewell water. Bacteria thrive in hot, dark, humid livewells especially when dead organic matter is present in in livewell water.  Remove dead bait and dead fish ASAP to reduce bacterial growth and reduce oxygen excessive consumption. *Saltwater contains more bacteria and mcro-organisms than freshwater.

LIVEWELL AIR VENTS

Gaseous livewell toxins are metabolic waste gases originating in livewell water as dissolved CO2 and dissolved ammonia.

Livewell vents and mechanical aerators: Water pumps, spray bars, air pumps, air tubing and bubble stones off-gas dissolved CO2 and ammonia gas. These electrical devices “ventilate, remove” metabolic toxins from livewell water.   Mechanical aerators are poor oxygenators.  Their primary purpose is not to oxygenate livewell water.

AIR VENTS: The livewell gas space is between the bottom of the livewell lid and the water surface. The boat must be moving to ventilate the livewell.

Air passing through livewell via air vents will be hot in the summer and cold in the winter and directly affect livewell water temperature.   Ambient air at ambient temperature flushes through the livewell only when the boat is moving @ 40-60 mph.

Toxic metabolic gases inside the livewell is usually reduced to safe concentrations by simply opening the livewell lid occasionally during the day or night to get bait, adding tournament game fish or just checking often to see if all is well inside the livewell and a that fish has not dies.   Air vents installed in livewell lids on boat livewells ventilate livewell gas space with ambient air. Air is not oxygen

Hot summer temperatures and freezing cold winter ambient air temperatures:

FACT: In the summer,  the livewell gas space is ventilated with hot air, ambient temperature 90 – 100+ F. Expect hot summer air temperatures to transfer heat to livewell water increasing livewell water temperature to air temperature.   Hotter water is inversely proportional to dissolved oxygen, air is always the limiting factor for dissolved oxygen. The increased air temperature may be more problematic in insulated livewells exposed to continuous high summer air temperatures > 80 – 100 F.

FACT:  In the winter, freezing cold air temperatures will also cause adverse low water temperature problems in livewell water.   Livewell  air vents have advantages while the boat and air is moving through the air vents and serious disadvantages with very limited oxygenation capability in all overstocked livewell.

FACT: NEVER OVERSTOCK YOUR LIVEWELL  BY ONLY 1 FISH. YOUR LIVE BAIT AND TOURNAMENT FISH WILL SUFFOCATE FROM LACK OF DISSOLVED OXYGEN WHEN YOUR LIVEWELL IS OVERSTOCKED, ESPECIALLY IN THE SUMMER.

INSTALLING LIVEWELL AIR VENTS

Instillation requires 2 permanent holes several inches wide cut into the livewell lid. Vent shafts extend several below the livewell lid causing an obstruction that can physically injure jumping fish. Any physical injury during transported increases the possibility of mortality and of course, the “dead fish penalty.”

WATER  FLOW IN THE LIVEWELL- WHICH DIRECTION, HOW MUCH FLOW — IS ALL THAT FLOWING WATER REALLY NECESSARY

Fact: Flowing water inside a livewell or bait tank is unnecessary during active transports, if the livewell water quality (specifically DO Saturation) is maintained continuously within safe limits for the total biomass of fish…

“MINIMAL SAFE OXYGENATION” is 100% DO Saturation or greater. The is the DO Saturation water quality Fish Hatchery Gold Standard for all live fish transport whether 1 fish or 1000 fish are being transported in the haul tank. 

Sloshing water in moving boat livewells continuously stirs and mixes water.  Livewell mortality is usually caused because the water quality is deadly. Makes no difference whether the deadly water is moving or flowing in any direction whether your are above or below the earth’s equator.

Ocean ram breather species (tuna) need flowing water in their natural ocean environment because ocean water contains a small limited amount of dissolved oxygen.  Ram breathers  don’t take 2 breaths from the same  water. Oxygen enriched livewell water eliminates the need for large volumes of flowing water over the gills. Ram breathers live fine in oxygenated livewells (supplemental oxygen > 21%) without high volumes of water flowing through gills  inside oxygenated livewells.

LIVE BAIT FISH AND GAME FISH ARE NOT IGNORANT LITTLE ANIMALS CONTRARY TO POPULAR BELIEF AND MAGAZINE ARTICLES

Live bait and fish behavior inside livewells, bait tanks and ice chest:

Contrary to popular belief, plenty of  mis-information and myths, live bait and fish are not stupid animals that gang up in square corners of livewells, bait tanks and ice chest with 90 degree corners and bang their heads into walls, get red-nose and commit suicide, that’s really silly. This aberrant behavior is seen only when the livewell water quality is deadly and absolutely intolerable.

Why do live bait gang up in square 90 degree livewell corners? The horror of suffocation and innate need to escape or die.

FACT: This behavior indicates deadly poor livewell water quality.  Animals are trying desperately to get out  and avoid that deadly toxic water inside the box… like a man in a sealed in an air tight box with no oxygen, suffocating, scratching the walls until his fingernails are torn and bloody, desperately trying to get out of the box and breathe. This kind of stress is like “waterboarding.”     http://en.wikipedia.org/wiki/Waterboarding

FOAM ON THE WATER SURFACE MEANS FISH STRESS – WATER QUALITY PROBLEMS

Excessive mucous production is the first autonomic response fish have to any and all stress stimuli. The greater the stressor the more mucus they produce. The increased mucus production between the skin and scales pushes the scales further away from the skin than normal (unstressed conditions) making the scales more susceptible to damage and sloughing off. Mucus is an automatic protective response to stress.  Mucus and scales protect the skin from abrasion, trauma and disease.

Foam is caused when air bubbles through livewell water containing protein (mucus). More mucus causes more foam.   Eliminate the stressors, correct the poor water quality and the foam disappears.

Low oxygen stress (suffocation) is the deadliest, most serious stressor for captive wild bait fish and mature game fish being transported in livewells and bait tanks. Oxygen deprivation causes brain and central nervous system damage and kills fish in minutes.

Antifoaming agents: Antifoaming agents are detergents that reduce the surface tension and cause the foam bubbles to collapse back into a liquid state.

1. Detergents are cosmetic, mask poor water quality and make foam disappear, makes  pore  quality livewell water look better. That’s all.

2. Detergents cause the foam bubbles to burst at the water surface improve gas diffusion into water and aeration at the surface of the water. The gas molecules (oxygen and CO2)  have less distance to travel into and out of livewell water when there is no foam on the surface that obstructs and retards  ambient air diffusion into the water.

SUMMARY

Transporting live healthy bait and game fish in livewell and bait tanks is the goal.

Maintaining safe livewell water quality is more important than the shape of the livewell box.

Livewell and bait tank oxygenation is more important than mechanical aeration and high volume livewell pumps, bells and buzzers. Oxygen and air are different gases, do not confuse the 2 gases.

Livewell ventilation (metabolic toxins) is important, but more important is sustaining minimal safe dissolved oxygen saturation continuously during live transports *when the livewell is full of fish.

Learn live bait and fish language:   Pay attention to foam on the water surface, live bait and fish behavior, schooling patterns inside the livewell or bait tank, fish location within the livewell water column, what your livewell water looks like (turbidity and surface foam)  smells like, and especially fish/live bait respiratory rate.