From Out of the Past - Part VIII

          At this point you may be thinking that if there was sufficient reason to establish numerous factories for the processing of horseshoe crabs into fertilizer, then there must be sufficient quantities of horseshoe crabs in Delaware Bay to supply those factories.  There was.  However, trying to determine exact numbers for the harvested populations of horseshoe crabs over the years is, as best, a tricky proposition.  That’s because record-keeping was not always an exact science – particularly before the turn of the century and also in the years since.  Additionally, there is the matter of who is doing the record-keeping.  Is it the local government, the state government, federal fishery agencies, the fertilizer factory people, commercial fisheries, or some other quasi-legislative entity willing, or able, to count thousands, indeed millions, of marine creatures?  Suffice it to say, there were many stakeholders in this particular commercial enterprise.
          The chart below represents some very rough estimates on the number of adult horseshoe crabs harvested in Delaware Bay over more than a century of record-keeping.  Please keep in mind that these numbers (averages actually) only represent a portion of the total adult population.  As Carl Shuster once stated, “While there is no sound estimate of the peak numbers of Limulus that existed in Delaware Bay area at some time in the past, as in Colonial days, the adult fraction of that population must have included several millions, perhaps tens of millions.”  Shuster points out that it would be “difficult to conceive how over 4 million could be harvested in one year in the 1870s” if the TOTAL population in Delaware Bay wasn’t several times that number.

Year	# of Horseshoe Crabs Harvested
1871	4,300,000
1881	1,693,000
1891	1,231,000
1901	1,826,000
1911	2,310,000
1921	1,563,000
1931	797,000
1941	286,000
1951	115,000
1961	42,000
1971	274,000
1981	923,000
1991	422,000