Store Spanish mackerels in the coldest part of your refrigerator. For long term storage they can be frozen.
How to Freeze Better at Home
Shelf Life: Up to five days fresh, several months frozen.
Mackerel can be grilled, broiled, smoked, poached, roasted or added to soups. For firmer flesh, marinate it in acid (citrus juice or vinegar) before cooking.
Mackerel’s distinctive flavor pairs well with allspice, cloves, chilies, citrus, vinegar, ginger, scallions, saffron threads, and most fresh herbs.
Whole Fish Recipes & Techniques