Just like striped bass and salmon, river herring are anadromous; they spawn in freshwater rivers yet spend most of their lives at sea. Out of the 24 assessed runs, 92 percent are determined to be badly depleted. While loss of spawning habitat due to dams and other obstructions is certainly responsible for some of the decline, remediation has proved unsuccessful in many cases. Pursuant to an Atlantic States Marine Fisheries Commission mandate, most state fisheries have been shut down; others continue, subject to very small quotas, under state sustainable management plans. Yet, at sea, industrial fisheries for sea herring and mackerel are still allowed to kill unlimited amounts of river herring, usually taken as bycatch, and most of that is simply unaccounted for.