Fish is an essential part of Istanbul cuisine, and offers a flavorful alternative to kebabs. Many locals can tell at a glance just how many hours a fish has been out of the water. But with Istanbul's population now over 15 million, the once-abundant native fish are becoming scarcer, and prospects for the future are uncertain. Fishing stocks have been depleted by the use of large fishing boats, which are consequently now banned from June to September. However, fishing for sport is still allowed, and many people fish along the Bosphorus. Fishermen yell at passing boats that get too close and scare away the fish.
While perusing Istanbul's menus, keep an eye out for the following fish. In some cases, we've listed the months when they're most abundant, but you may also find them outside this time.

Barbun (bahr-boon): This little red mullet, which lives along the muddy seabed, can be caught year-round. A local delicacy, it's delicious when deep-fried, and is often served as a side dish or as a hot appetizer. No need to remove the bones—just crunch them down.
Cinekop (chee-neh-kohp): This young bluefish is popular when grilled, and is available from early October through the end of November.
Hamsi (hahm-see): This anchovy, in season from November to March, is a delicacy from the Black Sea. Natives cook this small fish dozens of ways—including fried, steamed, grilled, cooked in casseroles, and even added to cornbread. Hamsi are especially good when steamed in large trays with onions, tomatoes, green peppers, and lemons—creating a traditional dish called hamsi buğulama (hahm-see boo-oo-lah-mah).
İstavrit (ees-tahv-reet): This mackerel, generally served fried, is available throughout the year.
Kalkan (kahl-kahn): This delicious turbot lives in the Sea of Marmara, is best pan-fried, and is usually in the markets from December to April. As it's becoming rarer, you may find it only in upscale restaurants. It has round bones that locals call "buttons"; those with fewer bones are female.
Levrek (lehv-rehk): While its tastier wild cousins are expensive and hard to find, this farm-raised sea bass is cheap and available year-round. Although it's not wild, it's still worth a try—especially grilled.
Lüfer (lew-fehr): Its lack of a "fishy" taste makes this type of bluefish extremely popular in Istanbul. It's becoming rare—and expensive—and is usually available from late September to January.
Mezgit (mehz-geet): Fish-sellers hawk this whiting throughout the year. It's best either pan-fried or steamed with vegetables, though natives of Istanbul have never developed a real taste for its chicken-like flavor. (s3)