Fish Tales: Colorful Koi Populate Prospect Park's Lakes

During the dog days of summer, fish become less active in the lakes and ponds of New York City. The gilled creatures tend to stay near the bottom of the water in order to escape the sun’s harsh heat. Summer is not the best time for anglers. Like some humans, heat can cause fish stress, making them plunge deep into cooler parts of the lakes. This may be bad news for fisherman, but the summer is a great time for some quality fish watching.  

I was surprised to discover the large number of koi present in urban lakes. No one seems to know how the Cyprinus carpio, which are primarily domesticated ornamental fish, began to populate these lakes. I suspect that the increase in koi is due to people who move and decide to abandon their aquatic pets in the nearest bodies of water. But no matter how or why, the result is that the multi-colored fish, that are usually meant to be decorative pond dwellers, now live happily in urban ponds and lakes amongst the other types of fish like, bluegills, sunfish, red-eared sliders and thousands of large-mouth bass.

Koi, which is a type of carp, have been a source of food for Asians for many centuries. First in China and then later in Japan, carp were not only food, but were also bred for their unique colors. In China, the breeding begot a species kids love: the goldfish. 

In the Japanese rice fields carps were bred to give the fish even different colored scales, thus giving birth to the “nishikigoi,” the Japanese word for brocaded carp. Koi have long live spans, even longer than humans. In Japan, the oldest documented koi lived for more than 200 years.

Prospect Park’s Lake and Lullwater have big koi populations, some measuring more than a three feet in length and weighing up to 50 pounds. The color range is also an interesting characteristic: some are snow white, other are spotted orange, black or red. Due to koi’s unique and bright coloring the beautiful fish have to be careful of predators. Unfortunately, unlike common carp and other fish, the colorful pond-dwellers cannot camouflage into their surroundings, therefore they are in susceptible to hungry predators.

However, koi bright colors make it ease for humans to spot, whipping their fins back and forth under the water’s surface. The best time to observe the large fish is in the spring as water temperature warms, but is not too hot. The best way to see koi and other fish is to wear the fisherman’s favorite type of shades: polarized sunglasses. Since sunlight reflects horizontally and more intensely off the water’s surface, the polarized lens’ block the sun’s horizontal glare and allow the wearer to see clearly without that annoying and harsh reflected light.