Effects of Rain and Drought

Community Contributed

By Glenn I. Teves, County Extension Agent, UH CTAHR

We’ve been in a drought for several years now. The dry winter into early spring was worrisome until last week’s storm brought welcome relief. But rains don’t always alleviate a dropping reservoir unless it arrives in moderate, not heavy amounts, and drops into Waikolu Valley. This storm resulted in heavy runoff and washed precious soil into the ocean. The water will be muddy until the dirt settles on the bottom and that’s not good. The drought had already left its mark.

Everything is connected. A less-than-average flow of artesian water percolating along the coast can adversely affect the fisheries habitat, resulting in a lower than average hatching of fingerlings or pua. Some of the edible seaweeds can also be affected by the lack of fresh water mixing with the sea water, such as limu `eleele.

In a drought, insects will seek out water. A good example is ants, who like to team up with honeydew-producing insects. Ants will protect aphids, mealy buds, whiteflies, and scales in exchange for honey dew for their food. These insects are known to suck plant juices and weaken them, while aphids and white flies are known to spread plant viruses on an array of crops such as melons, peppers, and tomatoes.

When it rains, centipedes and scorpions head for shelter and the warmth of a home, while slugs and African snails start seeking out new food. But the best thing about rain is it drowns insects like fruit flies, aphids, ants, and especially ground dwelling insects. This is like winter-kill, Hawaiian style.

All animals need water to survive, and will seek it out even if it’s the last thing they do. This goes for mice, mongoose, birds, and other feral animals, as well as cats and dogs. Farmers have experienced animals chewing on their drip irrigation systems, creating leaks and subsequently water loss. For livestock, drought brings low birthing and weaning weights, leading to losses for ranchers. Abortions result when cows don’t eat sufficient high quality food in critical times in pregnancy, leading to a smaller calf crop.

As ranchers try to reserve grass for later in the season, deer are jumping ahead, eating feed that ranchers are reserving for a not-so-rainy day. Due to feed shortages, livestock are forced to eat food they don’t normally eat, including poisonous plants. Of these, jimson weed is toxic and lantana can cause light photosensitivity rendering goats blind in strong sunlight. This all adds up to a shrinking bottom line.

Axis deer are adaptable, and can change eating habits to adjust to the environment. For farmers, it’s a never ending battle and I can only guestimate how much crop was lost, but I would venture to guess it’s close to a million dollars. The Maui County Office of Economic Development has sent out surveys to farmers to estimate impacts on their crops. If you’re interested in participating, you can pick up a copy at our office. We’re located next to the Ho`olehua Post Office.