| 国家 | 地点 | 描述 | 年代 | Qualitative Value | 参考文献 |
|---|---|---|---|---|---|
| Greenland | off Greenland | 1982 - 1996 | rare | 80685 | |
| United States (contiguous states) | Penobscot Bay, Maine | 1997 - 1997 | rare | 39299 | |
| United States (contiguous states) | Penobscot Bay, Maine | 1998 - 1998 | absent | 39299 | |
| Alaska | Bering Sea Shelf | 1990 - 1990 | 122396 |