Fish egg and larval surveys were carried out to map spawning grounds and to derive information on the adult spawning stock of Mackerel and Horse Mackerel. Each station has Id, time, date, position, sample and bottom depth, water temperature at 5m, 20m, 50m, 100m and maximum sample depth where appropriate, salinity at 20m, volume of water filtered during the tow, and Stage 1 egg counts for mackerel and horse mackerel. The Mackerel Egg Survey covers marine grounds in the North Atlantic Ocean, Celtic Seas and Bay of Biscay between Ireland and France. The survey has been running since 1977 and therefore provides important information about the distribution and timing of spawning in relation to climate change. Marine Institute surveys have been taking place since 2007 and have been initiated every three years including 2010, 2013 and 2016. At each egg station the GULF plankton sampler was towed on a v-shaped profile to within 5m of the bottom, or a maximum depth of 200m, whichever is greater. Data feeds into the stock assessment as fisheries independent information. The Fisheries Ecosystem Advisory Services (FEAS) section of the Marine Institute (Ireland) are part of an international consortium of eight European countries that run the international mackerel and horse mackerel egg surveys. Data complete for surveys completed since 2007.