Section 20. The director shall assist and co-operate with coastal cities and towns for the purpose of increasing the supply of shellfish and exterminating the enemies thereof within their borders, and for this purpose may expend such sums as may be appropriated therefor. The expenditure of any funds so appropriated shall be apportioned by the director among said coastal cities and towns in such amounts as will, in his opinion, effect the greatest amount of relief and assistance to the shellfish industry; provided, that no money shall be expended hereunder in any such city or town for the purpose of such relief or assistance unless such city or town, within one year prior to the date of such expenditure, shall have expended an amount equal to at least one fourth of the total cost of such work, or shall have contributed services or material of a value, as determined by the director, equal to such proportion. The work of increasing the supply of shellfish and exterminating the enemies thereof in coastal cities and towns aided hereunder shall be done and expenditures therefor shall be made in such manner as the director may determine and in accordance with rules and regulations which the director shall make with respect thereto, which rules and regulations he is hereby authorized to make and enforce.

The director, in the operation of any plant for the treatment or purification or propagation of shellfish, is hereby authorized and directed to investigate and study methods for the treatment or purification of shellfish taken from areas determined under section seventy-four to be contaminated. The director, in the course of such investigation, shall confer with the state department of public health and may expend for expert, clerical and other services and expenses such sums as may be appropriated therefor. The director shall, before exercising the authority to assist and co-operate as provided in this section, receive the advice of the biologist of the division and a written opinion from him thereon.

The director, acting on behalf of the commonwealth and with the approval of the governor and council, may enter into contracts or agreements with agencies of the federal government or any private institute or corporation for carrying out research and laboratory work necessary for purposes of the treatment or purification of shellfish and the propagation of shellfish in the coastal areas of the commonwealth, and may expend such sums as may be appropriated for the purpose.