Most people tend to put away their fishing gear at the end of autumn or fish less frequently during the winter. Aside from the fact that the atmospheric conditions are often uncomfortable, people believe that it is more difficult to catch fish during winter with the same regularity as over the warmer months. Is this really the case?

In my experience winter fishing in the estuaries can regularly be very productive.  The trick is to figure out when the fish are likely to feed and specifically target these periods. Many species of fish actually move into the estuaries in autumn and live there throughout the winter. In New Zealand kahawai and trevally both do this and often it is the larger specimens that over winter in the shallow harbours. Some of these fish hunt alone and can be impressively proportioned.

In winter what does happen though is that fish do not need to feed as often in the cooler water and when they do the period of feeding activity is generally shorter.

I’ve been corresponding with Dr Neill Herbert a fish physiologist from Auckland University to try and gain some insight as to what happens to fish metabolism as water temperatures cool over winter and use this information to see if there is anything that can be done to boost catch rates.

There is no doubt that temperature influences several processes which are directly or indirectly related to food demand and feeding activity. Except for some representatives of the tuna family, fish are exothermic animals that do not regulate their body temperature and body temperature fluctuates with that of the environment (with a difference of about 0.5 degrees Celcius).

Dr Herbert confirmed that “What this means is that as the temperature cools fish slow down and feed less as a result of thermal dependent metabolism and its influence in two areas:

• Low temperature slows metabolism so the drive to feed (i.e. the drive to obtain energy) lessens.
• Muscle function (“twitch”) slows under cooler, less optimal conditions so fish cannot swim as fast. (Some species of tuna can however keep muscle temperature quite high with heat exchangers so they can swim fast in cool waters)”

Summarising, as fish metabolism and muscle function slow over winter the desire to feed and chase prey diminishes. This explains the reduced incidence of visible fish activity and the shorter windows where fish feed actively. What this means is that fish may still be present at favoured locations but they become more opportunistic in their feeding behaviour.

My friend Jim Lanfear, the UK lure maker, owns and manages a trout farm. He has noticed that trout have different feeding behaviours depending on the season.

“They have a distinct pattern in the summer, winter and spring periods in particular. Wild fish, of maturity will, of course, have their spawning to consider, too. We are told that this is governed primarily by daylight length but also temperature and is an understandable response to the needs of survival. Summer is feeding time, autumn spawning, winter conserving energy, spring a recovery period. Clearly, temperature is a big factor, whatever the season; or to be more accurate, from an angling point of view, relative temperature. If the water goes from 6 degrees Celcius up to 8 degrees Celcius trout will feed well in the winter, if it goes from 10 degrees Celcius down to 8 degrees Celcius, they’ll go slow and become torpid. It’s still 8 degrees Celcius but it is relative. I’m sure it’s the same in coastal waters, too”.

What does this mean and how can anglers who fish from the shore into shallow water (less than ~ 8 metres) take advantage of this information?

Firstly, it is important to find the times of the day when any fish present feed actively. If you keep a fishing dairy and record the details of each session then it should be relatively easy to analyse the data and find the winter feeding periods.

Where I fish in on the local harbour flats this means:-

• Early – mid morning when the weather is still, preferably negligible wind with the sun on the water. Under these circumstances the relative water temperature is rising slowly during the morning which is ideal.
• Outgoing tide with a minimal tide run (difference between low and high tide of less than 3.0 metres). This concentrates prey into small areas and makes it easier for predatory fish to track it down without expending too much energy.
• Clear water. This makes it easier for fish to spot, locate and herd bait into tight schools.

I’ve noticed that if the wind springs up, especially with a Southerly aspect, and starts to ruffle the surface of the water then fish activity shuts down quickly. This is probably because, especially in shallow water, when the surface of the water is ruffled it cools more rapidly and the water temperature drops quickly. All of a sudden the dropping temperature difference that Jim Lanfear mentions becomes important. This may explain nicely the fishing maxim “when the wind is from the South, fish shut their mouths”!

As fish metabolism slows then it is very important to slow down the rate at which the lure is worked. If the angler retrieves the lure too quickly then it not only looks unnatural but also would take too much energy to chase down. Fish are much more likely to consistently nail a slow-twitched lure, presented near the bottom, in winter than a popper. These slow twitched lures are normally fished with braid so that every take, irrespective of how gentle, is transmitted back to the angler who can take appropriate action.

For more information on fishing soft plastics and using braid click on:- https://activeanglingnz.com/2016/03/07/soft-plastic-fundamentals/ and https://activeanglingnz.com/2016/02/23/tips-for-spinning-with-fused-braid/

Another thing that I have noticed about fishing in winter is that if the weather turns gnarly for many days on end and the water ends up discoloured then fish are forced to feed on items that are readily available on the bottom. This means that crabs move to the top of the menu simply because they are relatively easy to find. Using a slowly retrieved crab imitation can be deadly if the water is discoloured.

In conclusion, fishing in winter requires some careful thought. Identify areas where fish typically congregate at certain stages of the tide (especially low) and target these when the conditions are ideal with a slowly retrieved lure. If you have to fish in unfavourable conditions then try to modify your approach to optimise your chances of success. In winter, the old adage that one good fish can be the difference between a poor day and a great day can often hold true.