9.—(1) The Harbour Authority shall take all such measures as may be reasonably practicable to prevent any significantly detrimental interruption of the free passage of fish in the fishery during the construction of any specified work.
(2) If by reason of—
(a)the construction of a specified work; or
(b)the failure of any such work;
damage to the fishery is caused or the Agency has reason to expect that such damage may be caused, the Agency may serve written notice on the Harbour Authority requiring it to take such steps as may be reasonably practicable to make good the damage, or, as the case may be, to protect the fishery against such damage.
(3) If within such time as may be reasonably practicable for that purpose after the receipt of written notice from the Agency of any damage to a fishery, the Harbour Authority fails to take such steps as are described in sub-paragraph (2), the Agency may take those steps and may recover from the Harbour Authority the expense reasonably incurred by it in doing so.
(4) In any case where immediate action by the Agency is reasonably required in order to secure that the risk of damage to the fishery is avoided or reduced, the Agency may take such steps as are reasonable for the purpose, and may recover from the Harbour Authority the reasonable cost of so doing provided that written notice specifying those steps is served on the Harbour Authority as soon as reasonably practicable after the Agency has taken, or commenced to take, the steps specified in the notice.